In this work, we investigate the 2014–2015 neutrino flare associated with the blazar TXS 0506+056 and a recently discovered muon neutrino event IceCube-200107A in spatial coincidence with the blazar 4FGL J0955.1+3551, under the framework of a two-zone radiation model of blazars where an inner/outer blob close to/far from the supermassive black hole is invoked. An interesting feature that the...
The theoretical description of energetic particle transport near interplanetary shocks in the inner and outer Heliosphere and in other astrophysical contexts usually follows a diffusive paradigm. By means of scattering of particles at magnetic irregularities upstream and downstream of the shock, particles can be moved back and forth across the shock discontinuity and gain energy, forming...
In recent years, high-energy gamma-ray emission has been detected from star-forming galaxies in the local universe, including M82, NGC 253, Arp 220 and M33. The bulk of this emission is thought to be of hadronic origin, arising from the interactions of cosmic rays (CRs) with the interstellar medium of their host galaxy. More distant star-forming galaxies would also presumably be bright in...
The under-explored MeV band has an extremely rich scientific potential. Awaiting an all-sky MeV mission, it is now the prime time to take full advantage of the capabilities of the Fermi Large Area Telescope to explore this regime. With more than 12 years of the best available dataset (Pass8), we have developed an all-sky analysis to build a sensitive catalog of sources from 20 to 200 MeV. This...
The landscape of high- and ultra-high-energy astrophysics has changed in the last decade, in large part owing to the inflow of data collected by cosmic-ray, gamma-ray, and neutrino observatories. At the dawn of the multimessenger era, the interpretation of these observations within a consistent framework is important to elucidate the open questions in this field. CRPropa 3.2 is a Monte Carlo...
The nature of the GeV gamma-ray Galactic center excess (GCE) in the data of Fermi-LAT is still under investigation. Different techniques, such as template fitting and photon-count statistical methods, have been applied in the past few years in order to disentangle between a GCE coming from sub-threshold point sources or rather from diffuse emissions, such as the dark matter annihilation in the...
Neutrino-emitting blazars may accelerate cosmic ray (CR) protons at the inner regions of the jet, where most of the magnetic energy is likely to be dissipated. In this picture, the spectrum of neutrinos and gamma-rays that leave the source is shaped by the soft photon fields that the parent hadrons encounter before leaving the source. We build a lepto-hadronic emission model based on particle...
Energetic, non-thermal electrons are commonly observed both upstream and immediately downstream from the Earth’s quasi-perpendicular bow shock (Gosling, 1989). Upstream the energetic electrons are generally field-aligned beams, whereas downstream the flux of them is generally most intense in the direction perpendicular to the magnetic field. However, the acceleration mechanism of these...
Energetic particles generated by interplanetary shocks can drain a non-negligible fraction of the upstream ram pressure. We have selected a sample of shocks observed in-situ at 1 AU by the ACE and Wind spacecraft from the CfA Interplanetary Shock Database, which provides high-resolution data on solar wind plasma, shock parameters, and the local magnetic field. Time-series of the non-Maxwellian...
At very high energies (VHE), the emission of gamma rays is dominated by discrete sources. Due to the limited resolution and sensitivity of current-generation instruments, only a small fraction of the total Galactic population of VHE gamma-ray sources has been significantly detected. The larger part of the population can be expected to contribute as a diffuse signal alongside emission...
Deflections of ultra-high-energy cosmic rays (UHECRs) in extragalactic magnetic fields (EGMFs) decrease the expected directional correlations between UHECR arrival directions on the one hand and UHECR source positions and neutrino arrival directions on the other hand. We use the recently observed correlation between UHECRs and local star-forming galaxies by the Pierre Auger Observatory to put...
Recently, it has been shown that relatively low luminosity Fanaroff-Riley type 0 (FR-0) radio galaxies are a good candidate source class for a predominant fraction of cosmic rays (CR) accelerated to ultra-high energies (UHE, E>10^18 eV). FR-0s can potentially provide a significant fraction of the UHECR energy density as they are much more numerous in the local universe (up to a factor of ~5...
The global structure of the magnetic field inside the disk of our Galaxy is quite well described by dynamo action and constrained by Faraday rotation measurements. The Halo, on the other hand, is much more of an enigma. Other face-on spiral galaxies show spiral magnetic structures in their disk, like the Milky Way, showing that our magnetic field is a rather typical feature for such class of...
The detection of the flaring gamma-ray blazar TXS 0506+056 in spatial and temporal coincidence with the high-energy neutrino IC-170922A represents a milestone for multi-messenger astronomy. The prompt multi-wavelength coverage from several ground- and space-based facilities of this special event was enabled thanks to the key role of the Fermi-Large Area Telescope (LAT), continuously...
The Southern Wide-field Gamma-ray Observatory is a proposed ground-based gamma-ray detector that will be located in the Southern Hemisphere and is currently in its design phase. In this contribution, we will outline the prospects for Galactic science with this Observatory. Particular focus will be given to the detectability of extended sources, such as gamma-ray halos around pulsars;...
Ultra High Energy cosmogenic neutrinos may represent a unique opportunity
to unveil possible new physics interactions in the neutrino sector. At
this regard, we have investigated the effects on high and ultrahigh energy
active neutrino fluxes due to active-sterile secret interactions mediated
by a new pseudoscalar particle. These interactions become relevant at
very different energy...
Various observations are revealing the widespread occurrence of fast and powerful winds in active galactic nuclei (AGN) that are distinct from relativistic jets, likely launched from accretion disks. Such winds can harbor collisionless shocks at different locations that may induce acceleration of protons and electrons and consequent nonthermal emission. We focus on the inner regions of the...
IceCube has observed an excess of neutrino events over expectations from the isotropic background from the direction of NGC 1068. The excess is inconsistent with background expectations at the level of 2.9σ after accounting for statitsical trials. Even though the excess is not statistical significant yet, it is interesting to entertain the possibility that it corresponds to a real signal....
Among the information provided by high energy neutrinos, a promising possibility is to analyze the effects of a Violation of Equivalence Principle (VEP) on neutrino oscillations. We analyze the IceCube data on atmospheric neutrino fluxes under the assumption of a VEP and obtain updated constraints on the parameter space with the benchmark choice that neutrinos with different masses couple with...
Growing multispacecraft networks are broadening the opportunity of measuring energy spectra of energetic particles at interplanetary shocks over three decades or more in energy at the same distance (different from 1 AU) from the Sun. Energetic particles spectra at interplanetary shocks often exhibit a non-power law shape, even within two energy decades. We have introduced a 1D transport...
We recently proposed that cosmic rays are first accelerated at the redshift of z~ 20 by supernova remnants of first stars without the large scale magnetic field. In this talk, we are going to talk about the large scale magnetic field generation by the first cosmic rays. We show that even though the current and charge neutralities are initially satisfied, the current neutrality is eventually...
The CHANG-ES (Continuum HAlos in Nearby Galaxies - an EVLA Survey) project has observed a sample of 35 edge-on spiral galaxies with the JVLA in C- and L-band. The observations in all Stokes parameters provide polarization information and for 16 galaxies with extended emission it is possible to describe the large scale magnetic field structure in their halos. We exemplify a few of these objects...
Whether studying neutrinos for their own sake or as a messenger particle, neutrino cross-sections are critically important for numerous analyses. On the low energy side, measurements from accelerator experiments reach up to a few 100s of GeV. On the high energy side, neutrino-earth absorption measurements extend down to a few TeV. The intermediate energy range has yet to be measured...
The IceCube neutrino observatory detects neutrinos at energies orders of magnitude higher than those accessible to current neutrino accelerators. Above 40 TeV, neutrinos traveling through the Earth will be absorbed as they interact via charge current interactions with nuclei, creating a deficit of Earth-crossing neutrinos detected at IceCube. In this analysis we use the Earth as a target to...
In July of 2019, the IceCube experiment detected a high-energy neutrino from the direction of the powerful quasar PKS 1502+106. I discuss the results of multi-wavelength and multi-messenger modeling of this source, using a fully self-consistent one-zone model that includes the contribution of radiation fields external to the jet. Three distinct activity states of the blazar can be identified:...
The Astrophysical Multimessenger Observatory Network (AMON), has developed a real-time multi-messenger alert program. The system performs coincidence analyses of datasets from gamma-ray and neutrino detectors, making the Neutrino-Electromagnetic (NuEM) alert channel. For these analyses, AMON takes advantage of sub-threshold events, i.e., events that by themselves are not significant in the...
We study the latitudinal extent of the impulsive solar energetic particle (SEP) events of 2000 June 10 and 2001 December 26 using energetic electron observations from the ACE and Ulysses. We investigate the effects of particle source and transport on the profiles. We get the best fit parameters for simulations by comparing simulations with the two spacecraft observations. We show that...
On November 29, 2020 active region 12790 was located just beyond the east limb of the Sun as viewed by Earth. It erupted at 12:34UT with an M4.4 flare (as measured by GOES) and launched a coronal mass ejection (CME) traveling ~1700 km/s. Not surprisingly, this fast CME drove a shock that accelerated particles up to tens of MeV/nuc. More unusual was that these solar energetic particles...
We present the phenomenological implications of the micro-physics of cosmic-ray (CR) diffusion as resulting from particle scattering onto the three modes in which Magneto-Hydro-Dynamics (MHD) cascades are decomposed. We calculate the diffusion coefficients from first principles based on reasonable choices of the physical quantities characterizing the different environments of our Galaxy,...
The Fermi Large Area Telescope (LAT) has been detecting hundreds of Galactic sources, most of which are pulsars. Many Galactic sources are still undetected or unresolved due to their low flux, below the Fermi LAT sensitivity, or because of foreground and source confusion. Moreover, among the many unassociated sources, which are one third of the detected sources, a large amount may have...
Blazars are a subclass of active galaxies with jets closely aligned to the observer's line of sight. In addition, they are the most powerful persistent sources across the electromagnetic spectrum in the universe. The detection of a high-energy neutrino from the flaring blazar TXS 0506+056 and the subsequent discovery of a neutrino excess from the same direction have naturally strengthened the...
High-energy astrophysical neutrinos have been observed by multiple telescopes in the last decade, but their sources still remained unknown. We address the problem of locating astrophysical neutrinos’ sources in a statistical manner. We show that blazars positionally associated with IceCube neutrino detections have stronger parsec-scale radio cores than the rest of the sample. The probability...
Measuring neutrino interactions with matter is arduous but rewarding. To date, experiments have measured the neutrino-nucleon cross section in the MeV-PeV range, using terrestrial and astrophysical neutrinos. We endeavor to push that measurement to the EeV scale, in order to test competing expectations of the deep structure of nucleons and possibly reveal new neutrino interactions. Cosmogenic...
The existence of a flux of prompt atmospheric neutrinos from the decay of heavy hadrons resulting from the interaction of cosmic rays with the atmospheric nuclei is predicted by theory. Very Large Volume Neutrino Telescopes, like Icecube, KM3NeT and Baikal-GVD, should be sensitive to this neutrino component, that represents a background for the neutrinos from far astrophysical sources....
The discovery of neutrino oscillation confirms neutrinos have mass and the Standard Model(SM) of particle physics is not complete. It needs an extension in order to accommodate the masses and mixing of neutrinos, which essentially leads to beyond SM(BSM) physics. The unknown couplings involving neutrinos, so-called the Non-Standard Interactions(NSIs)[1] may appear as a ’new physics’ in...
XMASS is multi-purpose experiment using liquid xenon and is located at the Kamioka Observatory in Japan. The detector consists of a liquid xenon with a single-phase of 832 kg active volume and has a low energy threshold, low backgrounds and large target mass. In XMASS, it is possible to verify the topics of low energy neutrino physics which would give hints on models beyond SM. Now we have...
The present study is an updated search for magnetic monopoles using data taken with the ANTARES neutrino telescope over a period of 10 years (January 2008 to December 2017). In accordance with some grand unification theories, magnetic monopoles could have been created during the phase of symmetry breaking in the early Universe, and accelerated by galactic magnetic fields. As a consequence of...
Strange quark matter (SQM) is a hypothetical type of matter composed of almost equal quantities of up, down and strange quarks. Massive SQM particles are called nuclearites. Nuclearites with masses greater than $10^{13}$ GeV and velocities of about 250 km/s (typical galactic velocities) could reach the Earth and interact with atoms and molecules of sea water within the sensitive volume of the...
The tau lepton’s supersymmetric partner, the stau, appears in some models as the next-to-lightest particle. This makes it also a long-lived particle. In this scenario, its signature is a long, dim and minimally ionizing track when traveling through the IceCube detector. Independent of their primary energy, the stau tracks appear like low-energy muons in the detector. A potential signal of...
The real-time follow-up of high energy events from neutrino observatories is a promising approach to identify their astrophysical origin. So far, it has provided compelling evidence for a neutrino counterpart: the flaring gamma-ray blazar TXS 0506+056 observed in coincidence with the high-energy neutrino IC170922A detected by IceCube. The detection of very-high-energy (VHE, E > 100 GeV) gamma...
The KM3NeT collaboration is currently building a new generation of large-volume water-Cherenkov neutrino telescopes in the Mediterranean sea. Two detectors, ARCA and ORCA, are under construction. They feature different neutrino energy thresholds: TeV range for ARCA and GeV range for ORCA. The main research goal of ORCA is the measurement of the neutrino mass ordering and atmospheric neutrino...
The Fermi LAT point source catalog contains 10 years of observational data between 50 MeV to 1 TeV. It contains 5064 point sources mostly consisting of BLLs (1131) and FSRQs (694), while pulsars (239) are the most numerous Galactic population. However, a quarter of detected sources remains unclassified and might hide new source classes. The classification is difficult due to bright, diffuse...
In this work, reservoir phenomenon in the decay phase of gradual solar energetic particle (SEP) events are investigated with two Helios and IMP 8 spacecraft from January 1976 to March 1980, and with two STEREO and SOHO spacecraft from January 2010 to September 2014. Using these data, sixty-two reservoir events of solar energetic protons were identified, and the effects of perpendicular...
Studies of high energy proton interactions have been basic inputs to understand the cosmic-ray spectra observed on the earth. Yet, the experimental knowledge with controlled beams has been limited. In fact, uncertainties of the forward hadron production are very large due to the lack of experimental data. The FASER experiment is proposed to measure particles, such as neutrinos and hypothetical...
Observations with the current generation of very-high-energy gamma-ray telescopes have revealed an astonishing variety of particle accelerators in the Milky Way, such as supernova remnants, pulsar wind nebulae, and binary systems. The upcoming Cherenkov Telescope Array (CTA) will be the first instrument to enable a survey of the entire Galactic plane in the energy range from a few tens of GeV...
We introduce the TELAMON program, which is using the Effelsberg 100-m telescope to monitor the radio spectra of active galactic nuclei (AGN) under scrutiny in astroparticle physics, namely TeV blazars and neutrino-associated AGN. Thanks to its large dish aperture and sensitive instrumentation, the Effelsberg telescope can yield superior radio data over other programs in the low flux-density...
The detection of the high-energy neutrino IC-170822A in spatial (within the error region) and temporal flare activity correlation with the blazar TXS 0506+056 allowed these objects to be considered as progenitor sources of neutrinos. Besides this, no more detection of this kind was reported. Some other neutrinos detected by IceCube show a spatial correlation (within the error region) from...
On 22 September 2017 IceCube reported a high-energy neutrino event which was found to be coincident with a flaring blazar, TXS 0506+056. This first multi-messenger observation hinted at blazars being sources of observed high-energy astrophysical neutrinos and raised a need for extensive correlation studies. Recent work shows that the internal absorption of gamma rays, and their interactions...
The first Fermi Large Area Telescope (LAT) catalog of gamma-ray transient sources (1FLT) comprises sources that were detected on monthly time intervals during the first decade of Fermi-LAT operations. The monthly time scale allows us to identify transient and variable sources that may have not been reported in Fermi-LAT general catalogs.
The analysis was performed for photon energies between...
In the past 15 years, observations of the Galaxy at high energies by Fermi-LAT, AGILE, INTEGRAL and very recently by NuSTAR and eROSITA have been shown to be very exciting, allowing discoveries of a variety of objects and unexpected breakthroughs. However, from a few hundreds of KeV to several tens of MeV, the Galaxy remains poorly explored. In this energy range the lack of sufficiently...
The next generation of neutrino telescopes, including Baikal-GVD, KM3NeT, P-ONE, TAMBO, and IceCube-Gen2, will be able to determine the flavor of high-energy astrophysical neutrinos with 10% uncertainties. With the aid of future neutrino oscillation experiments --- in particular JUNO, DUNE, and Hyper-Kamiokande --- the regions of flavor composition at Earth that are allowed by neutrino...
High-energy neutrinos are expected to be produced during gamma-ray flares of blazars through the interaction of high-energy cosmic rays in the jet with photons. As a matter of fact, a high-energy neutrino event, IC-170922A, was detected at the time of a gamma-ray flare from blazar TXS 0506+056 at the level of 3 sigma significance. In this work, we present a statistical study of blazar...
The third release of the Fourth Catalog of Fermi-LAT Sources (4FGL-DR3), based on 12 years of data between 50 MeV and 1 TeV, is presented. Improvements in the analysis method relative to the original 4FGL catalog and new features are reviewed. The 4FGL-DR3 includes about 750 more sources than the previous release (4FGL-DR2, obtained with 10 years of data) and about 1500 more sources than 4FGL....
In this work we perform a population study of the H.E.S.S. Galactic Plane Survey (HGPS) catalogue. Namely, we analyze the flux, latitude and longitude distributions of gamma-ray sources detected by H.E.S.S. with the goal of inferring the main properties of galactic TeV source population.
We show that the total Milky Way luminosity in the 1-100 TeV energy range is relatively well constrained...
Shock acceleration is an important mechanism to accelerate energetic particles. Using test-particle simulations we investigate the time evolution of the accelerated particle energy spectrum in the downstream of a parallel shock with magnetic turbulence. From simulation results we obtain power-law energy spectra with a bend-over energy. It is shown that the bend-over energy increases with time....
Particle drifts perpendicular to the background magnetic field are proposed by some authors as an explanation for the very efficient perpendicular transport of solar energetic particles (SEPs). This process, however, competes with perpendicular diffusion caused by magnetic turbulence, which will also disrupt the drift patterns and reduce the efficiency of drift effects. The latter phenomenon...
With the improved sensitivity with respect to the previous generation, current space-borne and ground-based gamma-ray telescopes have made the number of gamma-ray sources detected at GeV-TeV energies increase many folds over the last decade. Many of the detected extended gamma-ray sources are not associated with any known sources at other wavelengths. Understanding the nature of these sources...
Among the many activities organized by the Outreach working group of the MAGIC (Major Atmospheric Gamma-ray Imaging Cherenkov) Collaboration, we would like to present the ongoing project #meetTheMAGICians. Under this hashtag, used on our social media pages (@MAGICtelescopes), we collect live streaming events on astroparticle physics topics, series of social media posts, videos and other...
Two-minute science (2'science) is a science communication project supported by early-career Greek astrophysicists. With this endeavor, which started in December 2020, we try to bridge the gap between the scientific community and the public. This project is based on the simple idea of writing short articles with an approximate reading time of two minutes. These articles cover several topics and...
The square kilometer array (KM2A) is the main array of the Large High Altitude Air Shower Observatory (LHAASO), which is the most sensitive gamma-ray detector for energies above a few tens of TeV. We are developing a software pipeline based on the experimental data, Monte-Carlo simulations and the pointing track of the arrays. The pipeline is able to perform 3D (sky images at different...
The optical sensors of the IceCube Neutrino Observatory are attached on vertical strings of cables. They were frozen into the ice in the deployment holes made by hot water drill. This hole ice, to the best of our knowledge, consists of a bubbly central column, with the remainder of the re-frozen volume being optically clear. The bubbly ice often blocks one or several of the calibration LEDs in...
The combined fit of the measured energy spectrum and shower depth distribution of ultra-high-energy cosmic rays is known to constrain the parameters of astrophysical scenarios with homogeneous source distributions. Further measurements show that the cosmic-ray arrival directions agree better with the directions and fluxes of catalogs of starburst galaxies and active galactic nuclei than with...
Gamma-ray observations ranging from hundreds of MeV to tens of TeV are a valuable tool for studying particle acceleration and diffusion within our galaxy. Supernova remnants, pulsar wind nebulae, and star-forming regions are the main particle accelerators in our local Galaxy. Constructing a coherent physical picture of these astrophysical objects requires the ability to distinguish extended...
Active galactic nuclei (AGNs) are amongst the most promising neutrino source candidates, due to their potential to accelerate cosmic rays in their relativistic jets. The IceCube observatory has already detected several events from the direction of known gamma-ray blazar AGNs, like TXS 0506+056 and, more recently, PKS 1502+106. Through numerical modeling, we can show that neutrino emission is...
The Cherenkov Telescope Array (CTA) is the future ground-based gamma-ray observatory and will be composed of two arrays of imaging atmospheric Cherenkov telescopes (IACTs) located in the Northern and Southern hemispheres respectively. The first CTA prototype telescope built on-site, the Large Size Telescope (LST-1), is under commissioning in La Palma and has already taken data on numerous...
The High Energy Stereoscopic System (H.E.S.S.) is one of the currently operating Imaging Atmospheric Cherenkov Telescopes. H.E.S.S. operates in the broad energy range from a few tens of GeV to more than 50 TeV reaching its best sensitivity around 1 TeV. In this contribution, we present an analysis technique, which is optimised for the detection at the highest energies accessible to H.E.S.S....
The Cherenkov Telescope Array (CTA) will be the next generation gamma-ray observatory with more than 100 telescopes located in the northern and southern hemispheres. It will be the major global instrument for very high energy astronomy over the next decade, offering one order of magnitude better flux sensitivity than current generation ground-based gamma-ray telescopes. Each telescope will...
We describe an outreach programme being undertaken at the Armagh Observatory and Planetarium (AOP) for the Cherenkov Telescope Array (CTA). Founded in 1790 and with a rich astronomical heritage, AOP today combines the research and education arms of our organisation to bring a research-informed outreach programme to the public, most often through our planetarium-related activities.
We...
Astronomy plays a major role in the scientific landscape of Namibia. Because of its excellent sky conditions, Namibia is not only frequently visited by astrophotographers but is also home to ground-based observatories like the High Energy Spectroscopic System (H.E.S.S.), in operation since 2002. Located near the Gamsberg mountain, H.E.S.S. performs groundbreaking science by detecting...
Deep Learning methods are among the state-of-art of several computer vision tasks, intelligent control systems, fast and reliable signal processing and inference in big data regimes. It is also a promising tool for scientific analysis such as gamma/hadron discrimination.
We present an approach based on Deep Learning for the regression of shower parameters, namely its core position and energy...
An upgrade to the IceCube Neutrino Telescope is currently under construction. For the Upgrade, seven new strings will be deployed in the central region of the 86 string IceCube detector to enhance the capability to detect neutrinos in the GeV range. One of the main science objectives of the Upgrade is an improved calibration of the IceCube detector to reduce systematic uncertainties related to...
Machine learning techniques are powerful tools for the classification of unidentified gamma-ray sources. We present a new approach based on dense and recurrent deep neural networks to classify unidentified or unassociated gamma-ray sources in the last release of the Fermi-LAT catalog (4FGL-DR2). Our method uses the actual measurements of the photon energy spectrum and time series as input for...
We constrain properties of ultrahigh energy cosmic ray source environments (and potentially astrophysical neutrino sources), including their photon temperature, gas density, size, magnetic field strength and coherence length, using UHECR and neutrino spectra and composition. Our analysis represents a new type of information on UHECR sources, independent of the mechanism responsible for the...
A major task in ground-based gamma-ray astrophysics analyses is to separate events caused by gamma rays from the overwhelming hadronic cosmic-ray background. In this talk we are interested in improving the gamma ray regime below 1 TeV, where the gamma and cosmic-ray separation becomes more difficult. Traditionally, the separation has been done in particle sampling arrays by selections on...
Recent discoveries of new features in Galactic cosmic-ray fluxes emphasize the importance of understanding the propagation of cosmic rays. HELIX (High Energy Light Isotope eXperiment) is designed to improve the measurements of light cosmic-ray isotopes, including the propagation clock isotope $^{10}\mathrm{Be}$ and stable secondary isotope $^{9}\mathrm{Be}$, which will be essential to study...
Modeling the extragalactic astroparticle skies involves reconstructing the 3D distribution of the most extreme sources in the Universe. Full-sky tomographic surveys at near-infrared wavelengths have already enabled the astroparticle community to bind the density of sources of astrophysical neutrinos and ultra-high cosmic rays (UHECRs), constrain the distribution of binary black-hole mergers...
Ground-based gamma-ray observatories such as the VERITAS array of imaging atmospheric Cherenkov telescopes provide insight into very-high-energy (VHE, E>100 GeV) astrophysical transient events. Examples include the evaporation of primordial black holes and gamma-ray bursts. Identifying such an event with a serendipitous location and time of occurrence is difficult. Thus, employing a robust...
The relative disposition of individual telescopes in the ground is one of the important factors in optimising the performance of a stereoscopic array of imaging atmospheric Cherenkov telescopes (IACTs). Following previous attempts at an automated survey of the broad parameter space involved using evolutionary algorithms, in this paper we will present a novel approach to optimising the array...
When very-high-energy gamma rays interact high in the Earth’s atmosphere, they produce cascades of particles that induce flashes of Cherenkov light. Imaging atmospheric Cherenkov telescopes (IACTs) detect these flashes and convert them into shower images that can be analyzed to extract the properties of the primary gamma ray. The dominant background for IACTs is comprised of images produced by...
IceCube is a cubic-kilometer scale neutrino telescope located at the geographic South Pole. The detector utilizes the extremely transparent Antarctic ice as a medium for detecting Cherenkov radiation from neutrino interactions. While the optical properties of the glacial ice are generally well modeled and understood, the uncertainties which remain are still the dominant source of systematic...
The IceCube Neutrino Observatory, located at the geographic South Pole, is the world's largest neutrino telescope, instrumenting 1 km³ of Antarctic ice with 5160 photosensors to detect Cherenkov light. For the IceCube Upgrade, to be deployed during the 2022-23 polar field season, and the enlarged detector IceCube-Gen2 several new optical sensor designs are under development. One of these...
The Cherenkov Telescope Array (CTA) will be the next generation ground-based observatory for very-high-energy gamma-ray astronomy, with the deployment of tens of highly sensitive and fast-reacting Cherenkov telescopes. It will cover a wide energy range (20 GeV - 300 TeV) with unprecedented sensitivity. Our study is focused on real-time detection at very-short timescales (from 1 to 100...
High energy neutrinos (E>10$^{17}$ eV) are detected cost-efficiently via the Askaryan effect in ice, where a particle cascade induced by the neutrino interaction produces coherent radio emission that can be picked up by antennas installed below the surface. A good knowledge of the firn properties is required to reconstruct the neutrino properties. In particular, a continuous monitoring of the...
We present results of the development of a calibration system for a project of a new Baksan Large Neutrino Telescope. The calibration system is based on fast blue and UV InGaN and AlGaN ultra bright and high power light emitting diodes (LEDs), a diffusing ball and fiber optics. Special fast electronic drivers for such LEDs were developed. The drivers are based on fast complementary and...
The TAIGA-experiment aims to implement a hybrid detection technique of Extensive Air Showers (EAS) at TeV to PeV energies, combining the wide angle Cherenkov timing array HiSCORE with Imaging Air Cherenkov Telescopes (IACTs). The detector currently consists of 89 HiSCORE stations and two IACTs, distributed over an area of about 1 km².
Our goal is to introduce a new reconstruction technique,...
The very-high-energy (VHE) emission from Centaurus A (Cen A) observed by the H.E.S.S. telescopes cannot be explained by simple synchrotron-self-Compton (SSC) models. Motivated by the reported UHECR hotspot in the direction of Cen A, we investigate a scenario in which excited isomer photons of heavy nuclei can account for these VHE photons.
Our fully self-consistent model includes a leptonic...
High energy cosmic rays and gamma rays interacting the atmosphere produce extensive air showers (EAS) of secondary particles emitting Cherenkov light. Being detected with a telescope this light forms "images" of the air shower. In the TAIGA project, in addition to images obtained experimentally, model data are widely used. The difficulty is that the computational models of the underlying...
The energy spectrum of cosmic rays extends over many orders of magnitude with a steep suppression of the flux at the highest energies. The energy spectrum of ultra-high energy cosmic rays (UHECR) is measured with great precision by the Pierre Auger Observatory (Auger) and Telescope Array. However, the two measured spectra show different slopes of the decrease at the highest energies. This...
Fanaroff Riley (FR) 0 radio galaxies form a low luminosity extension of the well established ultrahigh energy cosmic ray (UHECR) candidate accelerators FR-1 and FR-2 galaxies. Their much higher number density – up to a factor 5 more numerous compared to FR-1 with $z<= 0.05$ – makes them good candidate sources for an isotropic contribution to the observed UHECR flux. Here, acceleration and...
Gammapy is a community-developed, open source Python package for gamma-ray Astronomy, which is built on the scientific Python ecosystem Numpy, Scipy and Astropy. It provides methods for the analysis of gamma-ray data of many instruments including Imaging Atmospheric Cherenkov Telescopes, Water Cherenkov, as well as space based observatories.
Starting from event lists and a description of...
Muons from extensive air showers appear as rings in images taken with Cherenkov telescopes, such as VERITAS. These muon ring images are used for the calibration of the VERITAS telescopes, however this calibration process can be improved with a more efficient muon-identification algorithm. Convolutional neural networks (CNNs) are used in many state-of-the-art image-recognition systems and are...
Bouke Jung$^1$, Maarten de Jong$^2$, Paolo Fermani$^3$
on behalf of the KM3NeT collaboration
$^1$) University of Amsterdam, Nikhef
bjung@nikhef.nl
$^2$) Leiden University, Nikhef
mjg@nikhef.nl
$^3$) Sapienza Università di Roma
paolo.fermani@roma1.infn.it
Present and foreseen neutrino observatories, such as IceCube, P-ONE, GVD, Antares and KM3NeT have to operate in challenging...
KM3NeT is constructing two large neutrino detectors in the Mediterranean Sea: KM3NeT/ARCA, located near Sicily and aiming at neutrino astronomy, and KM3NeT/ORCA, located near Toulon and designed for neutrino oscillation studies.
The two detectors, together, will have hundreds of Detection Units (DUs) with 18 Digital Optical Modules (DOMs) maintained vertical by buoyancy, forming a large 3D...
Natural water and ice are currently used as optical detection media in large scale neutrino telescopes, such as IceCube, KM3NeT/ANTARES and GVD. When charged particles, such as those produced by high energy neutrino interactions, pass through ice or water at relativistic speeds they induce Cherenkov light emission. This is detected by the optical modules of neutrino telescopes. However, slower...
Imaging atmospheric Cherenkov telescopes, such as the Very Energetic Radiation Imaging Telescope Array System (VERITAS), are uniquely suited to resolve the detailed morphology of extended regions of gamma-ray emission. However, standard VERITAS data analysis techniques have insufficient sensitivity to gamma-ray sources spanning the VERITAS field of view (3.5°), due to difficulties with...
The large-scale deep underwater Cherenkov neutrino telescopes like Baikal-GVD, ANTARES or KM3NeT, require calibration and testing methods of their optical modules. These methods usually include laser-based systems which allow to check the telescope responses to the light and for real-time monitoring of the optical parameters of water such as absorption and scattering lengths, which show...
We present the results of the one year monitoring of absorption and scattering lengths of light with wave length 375÷532nm within the effective volume deep of underwater neutrino telescope Baikal-GVD, which were measured by a device «BAIKAL-5D». The «BAIKAL-5D» was installed during the 2020y winter expedition at a depth 1250 m. The device has a shaded point-like isotropic light source with...
Many projects want to share knowledge on particle and astroparticle physics (in particular, cosmic ray physics), however multi-messenger astroparticle-physics is still a young research field and hardly covered in educational curricula or in outreach. The astroparticle.online project, founded in 2018 within the framework of the German-Russian Astroparticle Data Life Cycle Initiative (GRADLCI),...
The IceCube Neutrino Observatory at the South Pole has tremendous emotional appeal—the extreme Antarctic environment coupled with the aura of a pioneering experiment that explores the universe in a new way. However, like with most cutting-edge experiments, it is still challenging to translate the exotic, demanding science into accessible language. We present three examples of recent successful...
A new method to reconstruct the slant depth of the maximum of the longitudinal profile (XmaxXmax) of high-energy showers initiated by gamma-rays as well as their energy (E0) are presented. The method were developed for gamma rays with energies ranging from a few hundred GeV to around 10 TeV. An estimator of Xmax is obtained, event-by-event, from its correlation with the distribution of the...
The Pierre Auger Observatory, sited in Malargüe, Argentina, is the largest observatory available for measuring ultra-high-energy cosmic rays (UHECR). The Auger Collaboration has measured and analysed an unprecedented number of UHECRs. Along with making important scientific discoveries, for example, the demonstration that cosmic rays above 8 EeV are of extragalactic origin and the observation...
The IceCube Neutrino Observatory at the geographic South Pole instruments a gigaton of glacial Antarctic ice with over 5000 photosensors. The detector, by now running for over a decade, will be upgraded with seven new densely instrumented strings. The project focuses on the improvement of low-energy and oscillation physics sensitivities as well as re-calibration of the existing detector. Over...
Baikal-GVD is a kilometre scale neutrino telescope currently under construction in Lake Baikal. Due to water currents in Lake Baikal, individual photomultiplier housings are mobile and can drift away from their initial position. In order to accurately determine the coordinates of the photomultipliers, the telescope is equipped with an acoustic positioning system. The system consists of a...
The Cherenkov Telescope Array (CTA) is the next-generation gamma-ray observatory
currently under construction.
It will improve over the current generation of imaging atmospheric Cherenkov telescopes (IACTs)
by at least one order of magnitude in sensitivity and be able to observe the whole
sky from a northern site in La Palma, Spain, and a southern one in Paranal, Chile.
CTA will also be...
Ground-based gamma-ray astronomy requires reconstructing extensive air showers initiated by gamma rays impinging on the atmosphere. Imaging atmospheric Cherenkov telescopes collect the Cherenkov light induced by secondary charged particles in extensive air showers, creating an image of the shower in a camera. This image is parametrized and used to evaluate the type, energy and arrival...
The Cherenkov Telescope Array (CTA), conceived as an array of tens of imaging atmospheric
Cherenkov telescopes (IACTs), is an international project for a next-generation ground-based
gamma-ray observatory, aiming to improve on the sensitivity of current-generation instruments
by an order of magnitude and provide energy coverage from 20 GeV to more than 300 TeV.
Arrays of IACTs probe the...
We present a new background estimation method for a search for largely extended TeV gamma-ray sources with instruments using the imaging atmospheric Cherenkov technique. This novel method does not rely on the assumption of source morphology and uses the cosmic-ray-like events (events that fail gamma-hadron-separation cuts using shower-shape parameters) collected from the given field to...
The ALTO project aims to build a particle detector array for very high energy gamma ray observations optimized for soft spectrum sources. The accurate reconstruction of gamma ray events, in particular their energies, using a surface array is an especially challenging problem at the low energies ALTO aims to optimize for. In this contribution, we leverage Convolutional Neural Networks (CNNs) to...
The IceCube Neutrino Observatory will be upgraded with more than 700 additional optical sensor modules and new calibration devices. Improved calibration will enhance IceCube’s physics capabilities both at low and high neutrino energies. An important ingredient for good angular resolution of the observatory is precise calibration of the positions of optical sensors. Ten acoustic modules, which...
KM3NeT is a deep-sea infrastructure composed of two neutrino telescopes being deployed in the Mediterranean Sea : ARCA, near Sicily in Italy, designed for neutrino astronomy and ORCA, near Toulon in France, designed for neutrino oscillations. These two telescopes are 3D arrays of optical modules used to detect the Cherenkov radiation, which is a signature of charged particles created in the...
The Fermi Masterclass is an international outreach event designed to give high-school students the unique opportunity to discover the world of High-Energy Astrophysics. Since 2017, various Italian universities and research institutes, guided by the National Institute for Nuclear Physics (INFN), organized a "full immersion" day of dedicated lectures and exercises in which students analysed real...
The CSES (China Seismo-Electromagnetic Satellite) is a multi-instrumental scientific space program whose objectives are to investigate the near-Earth electromagnetic, plasma and particle environment and for studying the seismo associated disturbances in the ionosphere-magnetosphere transition zone, the anthropogenic electromagnetic noise as well as the natural non-seismic electromagnetic...
The Large High Altitude Air Shower Observatory (LHAASO), is a multi-component experiment located at Daocheng (4410 m a.s.l.), Sichuan province, P.R. China. The identification of gamma rays from protons is an important foundation and premise for gamma ray research. In this paper, we use deep learning algorithm to extract the key features of events directly based on a large amount of original...
OCRA – Outreach Cosmic Ray Activities was born in 2018 as a national outreach project of INFN with the aim of collecting, within a national framework, the numerous public engagement activities in the field of cosmic ray physics already present at a local level in the divisions and laboratories. Since spring of 2020 OCRA offers also a series of online laboratories on its website...
Ultra-high-energy cosmic rays (UHECR) are the most energetic particles ever observed. What astrophysical sources are responsible for their immense acceleration remains unknown despite decades of research. In this talk, I will investigate whether low-luminosity gamma-ray bursts (llGRBs), short-lived cosmic explosions currently seen as one of the most promising acceleration candidates, can be...
The Probe Of Extreme Multi-Messenger Astrophysics (POEMMA) is designed to observe ultrahigh-energy cosmic rays (UHECRs) and cosmic neutrinos from space with sensitivity over the full celestial sky. Developed as a NASA Astrophysics Probe-class mission, POEMMA consists of two identical telescopes orbiting the Earth in a loose formation that observe extensive air showers (EAS) via air...
TIGERISS ( Trans-Iron Galactic Element Recorder for the International Space Station) is a natural evolution to space of the balloon-borne TIGER and SuperTIGER instruments discussed elsewhere at this conference. TIGERISS will be proposed to the next NASA Pioneers opportunity, anticipated in September 2021, as an ISS-attached mission to extend measurements of the relative abundances of galactic...
TAIGA experiment uses hybrid detection system for cosmic and gamma rays that currently includes three imaging atmospheric Cherenkov telescopes (IACTs). Previously we used convolutional neural networks to select gamma ray events and estimate the energy of the gamma rays based on an image from a single telescope. Subsequently we adapted these techniques to use data from multiple telescopes,...
The nonthermal source abundances of elements play a crucial role in the understanding of cosmic ray phenomena from a few GeV up to several tens of EeV. In this presentation a first systematic approach is shown that describes the change of the abundances from the thermal to the nonthermal state via diffusive shock acceleration by a temporally evolving shock. Hereby, not only time-dependent...
We analyze the Auger dipole anisotropy measurements below 8 EeV, to expose the existence of an individual source of the Galactic cosmic rays above $10^{17}$ eV. The source is incompatible with being in the direction of the Galactic center by a $\chi^2$/dof > 6. Interpreting the amplitude and direction of the Galactic HE Dipole in terms of a transient, we find:
a) The amplitude of the...
We discuss the production of multiple messengers including UHECR, EM radiation and neutrinos in Gamma-Ray Bursts in models with multiple interaction regions.
We demonstrate that standard high-luminosity bursts can explain the UHECR spectrum as as measured by the Pierre Auger Observatory, and derive the required source injection composition for different engine realisations. We discuss how...
We explain the observed multiwavelength photon spectrum of a number of BL Lac objects detected at very high energy (VHE, $E > 30$ GeV), using a lepto-hadronic emission model. The one-zone leptonic emission is employed to fit the synchrotron peak. Subsequently, the SSC spectrum is calculated, such that it extends up to the highest energy possible for the jet parameters considered. The data...
Background showers triggered by hadrons represent over 99.9% of all particles arriving at ground-based gamma-ray observatories. An important stage in the data analysis of these observatories, therefore, is the removal of hadron-triggered showers from gamma showers. Currently, the High-Altitude Water Cherenkov (HAWC) gamma-ray observatory employs an algorithm that is a single cut in two...
The KArlsruhe TRItium Neutrino (KATRIN) experiment performs a model-independent measurement of the electron neutrino mass with a design sensitivity of 0.2 eV (90% CL) after three full years of measurement time. KATRIN measures near the endpoint of the tritium beta spectrum, using the MAC-E filter principle by virtue of its 70 m long beamline. Its technological challenges include the...
For the in-ice component of the next generation neutrino observatory at the South Pole, IceCube-Gen2, a new sensor module is being developed, which is an evolution of the DEgg and mDOM sensors developed for the IceCube Upgrade. The sensor design features up to 18 4-inch PMTs distributed homogeneously in a borosilicate glass pressure vessel. Challenges arise for the mechanical design from the...
Blazars are a sub-category of radio-loud active galactic nuclei with relativistic jets pointing towards the observer. They exhibit non-thermal variable emission, which practically extends over the whole electromagnetic spectrum. Despite the plethora of multi-wavelength observations, the origin of the emission in blazar jets remains an open question. In this work, we construct a two-zone...
Blazars can show variability on a wide range of timescales. However, the search for periodicity in the gamma-ray emission of blazars remains an on-going challenge. This contribution will show the results obtained when a systematic pipeline is used to implement ten well-established methods for searching for periodicity. We analyze the most promising candidates selected from our previous work,...
The radio detection technique with advantages like inexpensive detector hardware and full year duty cycle can prove to be a vital player in cosmic-ray detection at the highest energies and can lead us to the discovery of high energy particle accelerators in the universe. However, radio detection has to deal with continuous irreducible background. The Galactic and thermal backgrounds, which...
The combined fit of the energy spectrum and mass composition data above $5\cdot10^{18}\:\mathrm{eV}$ suggested the presence of extragalactic sources ejecting ultra-high-energy cosmic rays with relatively low maximum energies, hard spectral indices and mixed chemical compositions, dominated by the contribution of intermediate mass groups. Here we present an extension of the fit to lower...
The Telescope Array (TA) cosmic rays detector located in the State of Utah in the United States is the largest ultra high energy cosmic rays detector in the northern hemisphere. The Telescope Array Low Energy Extension (TALE) fluorescence detector (FD) was added to TA in order to lower the detector's energy threshold, and has succeeded in measuring the cosmic rays energy spectrum down to PeV...
The Telescope Array Low-energy Extension (TALE) experiment is a hybrid air shower detector for the observation of air showers induced by cosmic rays with energy above 10$^{16}$ eV. The TALE detector consists of a Fluorescence Detector (FD) station with 10 FD telescopes located at the TA Middle Drum FD Station (itself made up of 14 FD telescopes), and a Surface Detector (SD) array made up of 80...
Telescope Array (TA) is the largest ultra-high-energy cosmic-ray (UHECR) observatory in the Northern Hemisphere. It is dedicated to detect extensive air showers (EAS) in hybrid mode, both by measuring the shower’s longitudinal profile with fluorescence telescopes and their particle footprint on the ground from the surface detector (SD) array. While fluorescence telescopes are can measure the...
IceCube is a cubic-kilometer Cherenkov detector installed in deep ice at the geographic South Pole. IceCube's surface array, IceTop, measures the electromagnetic signal and mainly low-energy muons from extensive air showers above several 100 TeV primary energy, with shower bundles and high-energy muons detected by the in-ice detectors. In combination, IceCube and IceTop provide unique...
Different experiments use different techniques to detect and reconstruct cosmic-ray events, yielding different energy scales. Having a method to compare the energy scales of different experiments with minimal uncertainty is necessary in order to make meaningful comparisons of their spectra and composition measurements, which are used to create global models of cosmic-ray sources, acceleration...
Benefiting from more than a decade of experience in WIMP searches with dual-phase xenon time projection chambers, the DARWIN (DARk matter WImp search with liquid xenoN) collaboration intends to build a next-generation detector involving 50 tonnes (40 tonnes active) of xenon. The primary goal of the observatory is to explore the entire experimentally accessible parameter space for WIMP masses...
The main purpose of the Baikal-GVD Data Quality Monitoring (DQM) system is to monitor the status of the detector and collected data. The system estimates quality of the recorded signals and performs the data validation. The DQM system is integrated with the Baikal-GVD’s unified software framework (“BARS”) and operates in quasi-online manner. This allows us to react promptly and effectively to...
The IceCube Upgrade is the first step towards the next-generation neutrino observatory at the South Pole, IceCube-Gen2, and will be installed in the central region of the existing array. The Upgrade will consist of 693 newly developed, densely spaced optical sensors and 50 standalone calibration devices, which will enhance IceCube's capabilities both at low and high neutrino energies. 402 of...
The IceCube Upgrade is an extension of the IceCube detector at the geographic South Pole. It consists of seven new strings with novel instrumentation. More than 430 multi-PMT optical modules called "mDOMs", housing 24 3-inch PMTs each, will be produced for the Upgrade. This will require testing and pre-calibration on a short timescale of more than 10,000 PMTs prior to assembly and deployment....
Extreme high synchrotron peaked blazars (EHBLs) are amongst the most powerful accelerators found in nature. Usually the synchrotron peak frequencyof an EHBL is above 10^17 Hz, i.e., lies in the range of medium to hard X-rays making them ideal sources to study particle acceleration and radiative processes. EHBL objects are commonly observed at energies beyond several TeV, making them powerful...
DIMS (Dark matter and Interstellar Meteoroid Study) is a new experiment aiming
to search for macroscopic dark matters and interstellar meteoroids. Nuclearites are nuggets of stable strange quark matter(SQM), neutral in charge and hypothetical super-heavy macroscopic particles (macros), and may be important components of the dark matter in our Universe. Nuclearites of galactic origins would...
In February 2019, a flaring state of the extreme blazar candidate TXS 1515-273 was registered by the Fermi-LAT, which triggered observations with the MAGIC telescopes and the X-ray satellites Swift, XMM-Newton and NuStar. The observations led to the discovery of the source at VHE gamma-rays and the detection of short time scales of variability (~1 h) in several X-ray bands.
The analysis of...
We propose a photon trap designed for improved photon detection efficiency in a cost-efficient way. Wavelength Shifting plastic sheets (WLS) are deployed at the bottom of a PMT, surrounded by dichroic film by which photons are efficiently trapped and guided to the PMT. We measured wave-length dependent transmittance of a commercially available dichroic film in water, a key variable determining...
We present results of advance studies of large area photomultipliers (PMTs) of different types from several manufacturers for use in a new Baksan Large Neutrino telescope. At first, requirements for photodetectors to be used in the telescope were formulated. Parameters of 8-inch, 10-inch and 20-inch PMTs were thoroughly studied. 8-inch PMTs under studies were ET9350 from ET Enterprises, R5912...
Interferometric measurements of the radio emission of extensive air showers allow reconstructing cosmic-ray properties. A recent simulation study with an idealised detector promised measurements of the depth of the shower maximum $X_\mathrm{max}$ with an accuracy better than 10$\,$g$\,$cm$^{-2}$.
In this contribution, we evaluate the potential of interferometric $X_\mathrm{max}$ measurements...
The first stage of the construction of the deep underwater neutrino telescope Baikal-GVD is planned to be completed in 2024. The second stage of the detector deployment is planned to be carried out using a data acquisition system based on fiber optic technologies, which will allow for an increased data throughput and looser, more flexible trigger conditions, thus maximizing the neutrino...
Powerful jets hosted by accreting super-massive black holes have long been candidates for the acceleration sites for high-energy extra-galactic cosmic rays, supported by the recent association of neutrinos from blazar TX0506+056. In the highly-aligned jets known as blazars, the X-ray to TeV radiation is usually attributed to inverse Compton scattering processes, but has not been clearly...
Cosmic neutrinos are unique probes of the high energy universe. IceCube has discovered a diffuse astrophysical neutrino flux since 2013, but their origin remains elusive. The potential sources could include, for example, active galactic nuclei, gamma-ray bursts and star burst galaxies. To resolve those scenarios, higher statistics and better angular resolution of astrophysical neutrinos are...
The highest-energy blazars exhibit non-thermal radiation extending beyond 1 TeV with high luminosities and strong variabilities, indicating extreme particle acceleration in their relativistic jets. The gamma-ray spectra of blazars contain information about the distribution and cooling processes of high-energy particles in jets, the extragalactic background light between the source and the...
Extreme high-frequency-peaked BL Lac objects (EHBLs) are the most energetic persistent sources in the universe. This contribution reports on long-term observing campaigns of tens of EHBLs that have been organized by the MAGIC collaboration to enlarge their population at VHE and understand the origin of their extreme properies. EHBLs are characterized by a spectral energy distribution (SED)...
The Pierre Auger Observatory investigates the properties of the highest-energy cosmic rays with unprecedented precision. The aim of the AugerPrime upgrade is to improve the sensitivity to the primary particle type. The improved mass sensitivity is the key to exploring the origin of the highest-energy particles in the Universe. The purpose of the Radio Detector (as part of AugerPrime) is to...
Massive black holes at the centers of galaxies can launch powerful wide-angle winds, which if sustained over time, can unbind the gas from the stellar bulges of galaxies. These winds, also known as ultra-fast outflows (UFOs), may be responsible for the observed scaling relation between the masses of the central black holes and the velocity dispersions of stars in galactic bulges. Propagating...
According to radiative models, radio galaxies are predicted to produce gamma rays from the earliest stages of their evolution onwards. The study of the high-energy emission from young radio sources is crucial for providing information on the most energetic processes associated with these sources, the actual region responsible for this emission, as well as the structure of the newly born radio...
Beams of ultra-relativistic electrons in blazar jets develop pair cascades interacting with ambient soft photons. Employing coupled kinetic equations with escape terms, we model the unsaturated pair cascade spectrum. We assume that the gamma rays predominantly scatter off recombination-line photons from clouds photoionised by the irradiation from the accretion disk and the jet. The cascade...
Current knowledge of the relative abundances and the energy spectra of the elemental mass groups of cosmic rays in the 10 TeV - 1 PeV interval are uncertain. This situation prevents carrying out precision tests that may lead to distinguish among the existing hypotheses on the origin and propagation of TeV cosmic rays in the galaxy. In order to learn more about the mass composition of these...
We test the hypothesis of an anisotropy in the mass of cosmic-ray primaries as a function of galactic latitude. The mass estimate is made using the depth of shower maximum, $X_{\text{max}}$, from hybrid events measured at the Pierre Auger Observatory. The 14 years of available data are split into on- and off-plane regions using the galactic latitude of each event to form two distributions in...
More than 40 years ago beginning of works on deep underwater high energy neutrino telescope projects (DUMAND and Baikal) inspired development of new photon detectors: large area photomultipliers (PMTs), multi small PMT optical modules, small PMTs equipped with wavelength shifting plates and rods and even small area solid state photon detectors for such kind application. Now days we witness...
At the Baksan Neutrino Observatory deployed in the Caucasus mountains, it is proposed to create, at a depth corresponding to about 4700 mwe, a large-volume neutrino detector based on a liquid scintillator with a target mass of 10 kt. The main physics goals of the detector are low-energy neutrino physics, astrophysics and geophysics.
The highest possible light yield is crucial for such...
OT081 is a luminous blazar well known for its variability in many energy bands.
The very-high-energy (VHE, E > 100 GeV) gamma-ray emission from the source was discovered by MAGIC and H.E.S.S. during flaring activity in July 2016, after a trigger from the LAT onboard the Fermi satellite.
From the analysis of the multiwavelength (MWL) light curves and of the broadband spectral energy...
Mass composition anisotropy is predicted by a number of theories describing sources of ultra-high-energy cosmic rays.
Event-by-event determination of a type of a primary cosmic-ray particle is impossible due to large shower-to-shower fluctuations, and the mass composition usually is obtained by averaging over some composition-sensitive observable determined independently for each extensive...
The Beamforming Elevated Array for COsmic Neutrinos (BEACON) is a novel detector concept that utilizes a radio interferometer atop a mountain to search for the radio emission from extensive air showers created by Earth-skimming tau neutrinos. The prototype, located at the White Mountain Research Station in California, consists of 4 crossed-dipole antennas operating in the 30-80 MHz range and...
M87 is a giant radio galaxy located in the Virgo Cluster, known to be a very high energy (VHE) gamma-ray source. As radio galaxies are considered the misaligned low-redshift counterparts of blazars, they are excellent laboratories for testing AGN emission models. M87 has been detected and monitored by Fermi-LAT and several atmospheric Cherenkov telescopes. Recently, the HAWC Collaboration has...
The flat-spectrum radio quasar QSO B1420+326 underwent an enhanced gamma-ray flux state seen by Fermi-LAT at the turn of 2019/2020. Compared to the low state both the position and luminosity of the two spectral energy distribution peaks changed by at least two orders of magnitude. The high state resulted in the discovery of the very-high-energy (>100 GeV) gamma-ray emission from the source by...
With the lowest background level ever reached by detectors searching for rare-events, XENON1T proved to be the most sensitive dark matter direct detection experiment on earth. The unprecedented low level of radioactivity reached, made the XENON1T experiment suitable also for other interesting rare-events searches including the neutrinoless double beta decay of 136Xe. In this talk I will report...
Cosmic ray data collected by the KASCADE air shower experiment are competitive in terms of quality and statistics with those of modern observatories. We present a novel mass composition analysis based on archival data acquired from 1998 to 2013 provided by the KASCADE Cosmic ray Data Center (KCDC). The analysis is based on modern machine learning techniques trained on simulation data provided...
P-ONE (Pacific Ocean Neutrino Explorer) collaboration was born with the aim of building a new large-scale neutrino telescope in the Pacific Ocean, at 2600 m b.s.l. in Cascadia Basin, off Vancouver Island.
The first steps aimed at the feasibility study and the characterization of the optical properties of the site with a first pathfinder project named STRAW (STRing for Absorption length in...
The low frequency segment of SKA in Australia will have an extremely dense antenna array spanning an area of roughly 0.5 km$^2$. It offers unique possibilities for high-resolution observations of air showers. Compared to LOFAR, it will have a much more homogeneous ground coverage, an increased frequency bandwidth (50-350 MHz), and the possibility to continuously observe with nearly 100% duty...
New optical sensors called the "D-Egg" have been developed for cost-effective instrumentation for the IceCube Upgrade. With two 8-inch high QE photomultipliers, they offer increased effective photocathode area while retaining as much of the successful IceCube Digital Optical Module (DOM) design as possible. Mass production of D-Eggs has started in 2020. By the end of 2021, there will be 310...
We present performance studies of a segmented optical module for the IceCube-Gen2 detector. Based on the experience gained in sensor development for the IceCube Upgrade, the new sensor will consist of up to 18 4-inch PMTs housed in a transparent pressure vessel, providing homogeneous 4 pi coverage. The use of custom moulded optical gel 'pads' around the PMTs enhances the photon capture rate...
The nature of dark matter remains an open question and could be in the form of warm dark matter. Sterile neutrinos are well motivated warm dark matter candidates and can decay into photons through mixing, which are consequently detectable by X-ray telescopes for sterile neutrino mass in the keV range. Moreover, axion-like particle are compelling warm dark matter candidates too and they can...
The preparation of next generation large-scale radio detectors such as GRAND requires to run massive air-shower simulations to evaluate the radio signal at each antenna position. Radio-Morphing was developed for this purpose. It is a semi-analytical tool that enables a fast computation of the radio signal emitted by any air-shower at any location, from the simulation data of one single...
The GRAPES-3 experiment is located at Ooty in India. It consists of a densely packed array of 400 plastic scintillator detectors (1 $m^{2}$ area each) with 8 m inter-detector separation and a large area (560 $m^{2}$) muon telescope. It measures the cosmic rays from a few TeV to over 10 PeV, thereby providing a substantial overlap with direct experiments as well as covering the knee region. The...
We present a reconstruction algorithm for extensive air showers with zenith angles between 65° and 85° measured with radio antennas in the 30-80 MHz band. Our algorithm is based on a signal model derived from CoREAS simulations which explicitly takes into account the asymmetries introduced by the superposition of charge-excess and geomagnetic radiation as well as by early-late effects. We...
KASCADE-Grande and its original array of KASCADE were dedicated to measure individual air showers of cosmic rays with great detail in the primary energy range of 100 TeV up to 1 EeV. The experiment has significantly contributed to investigations of the energy spectrum and chemical composition of cosmic rays in the transition region from galactic to extragalactic origin of cosmic rays as well...
Experimental efforts of the last decades have been unsuccessful in detecting WIMPs (Weakly Interacting Massive Particles) in the $10$-to-$10^4$ GeV/$c^2$ range, thus motivating the search for lighter dark matter. The DAMIC (DArk Matter In CCDs) at SNOLAB experiment aims for direct detection of light dark matter particles ($m_\chi < 10$ GeV/$c^2$) by means of CCDs (Charge-Coupled Devices)....
We present an updated analysis of the mass composition of cosmic rays in the $10^{17}$ to $10^{18}$ eV energy range. It is based on measurements with the LOFAR telescope of the depth of shower maximum, $X_{\mathrm{max}}$.
We review the improvements to the simulation-based reconstruction setup, as well as the selection method to obtain a minimally biased $X_\mathrm{max}$-dataset. Systematic...
The GRANDProto300 (GP300) array is a pathfinder of the Giant Radio Array for Neutrino Detection (GRAND) project. The deployment of the array, consisting of 300 antennas, will start in 2021 in a radio-quiet area of ~200km^2 near Lenghu (~3000 m a.s.l.) in China.
Serving as a test bench, the GP300 array is expected to realise techniques of autonomous radio detection such as identification...
The Radar Echo Telescope for Cosmic Rays (RET-CR) will use the radar echo technique to detect the in-ice continuation of an ultra high energy cosmic ray (UHECR) air shower. When a UHECR particle cascade propagates into a high-elevation ice sheet, it produces a dense in-ice cascade of charged particles which can reflect incoming radio waves. Through the detection of transmitted radio waves, the...
Multi-detector observations of individual air showers are critical to make significant progress to precisely determine cosmic-ray quantities such as mass and energy of individual events and thus bring us a step forward in answering the open questions in cosmic-ray physics. An enhancement of IceTop, the surface array of the IceCube Neutrino Observatory, is currently underway and includes adding...
DAMIC-M (Dark Matter in CCDs at Modane) is a near-future experiment aiming to search for low-mass dark matter particles through their interactions with silicon atoms in the bulk of charge-coupled devices (CCDs). This technique was pioneered by the DAMIC experiment at SNOLAB. Its successor DAMIC-M will have a 25 times larger detector mass and will employ a novel CCD technology (skipper...
CORSIKA 8 is a new framework for air shower simulations implemented in modern C++17, based on past experience with existing codes like CORSIKA 7. The flexibility of this framework allows for the inclusion of radio-emission calculations as an integral part of the program. Our design makes radio simulations general and gives the user the freedom to choose between different formalisms, such as...
High-resistivity silicon has made possible the fabrication of thick fully-depleted charge-coupled devices (CCDs) that have found a wide range of scientific applications, from particle detection to astronomical imaging. Their low noise and high charge collection efficiency allow us to reach unprecedented sensitivity to physical processes with low-energy transfers. The newly-developed...
Taiwan Astroparticle Radiowave Observatory for Geo-synchrotron Emissions (TAROGE) is antenna arrays sitting on high coastal mountains of Taiwan, pointing to the Pacific Ocean for the detection of near-horizon extensive air showers (EAS) induced by ultra-high energy cosmic rays and Earth-skimming tau neutrinos. TAROGE would improve the detection capability by collecting both the...
The TAROGE-M observatory is an autonomous antenna array on the top of Mt.~Melbourne ($\sim2700$ m altitude) in Antarctica, designed to detect radio pulses from ultra-high energy (over $10^{17}$ eV) air showers coming from near-horizon directions. The targeted sources include cosmic rays, Earth-skimming tau neutrinos, and most of all, the anomalous near-horizon upward-going events of yet...
The cosmic rays observed at Earth have propagated through the universe over cosmological distances. The propagation should effect both the observed spectrum of cosmic rays and the abundance of different nuclear species that are observed at each energy. By performing a combined fit of Telescope Array spectrum and composition measurements to a simple source model consisting of a universal...
Flat spectrum radio quasars (FSRQs) have been detected at TeV energies by ground-based atmospheric Cherenkov telescope mainly during flaring states. VERITAS is carrying out the first systematic and unbiased search for TeV emissions from a set of FSRQs. Fermi-LAT-detected FSRQs with positive declinations and extrapolated fluxes from the 3FHL catalog exceeding 1% Crab at >200 GeV after...
The DEAP-3600 experiment searches for dark matter via the interactions of WIMPs with a liquid argon target. The experiment is located at SNOLAB in Sudbury, Ontario 2 km underground to shield the detector from cosmic rays. The detector consists of an acrylic sphere with an inner diameter of ~170 cm containing ~3300 kg of liquid argon. Liquid argon is chosen as a target due to its ability to...
The Auger Engineering Radio Array (AERA) is currently the largest array of radio antennas for the detection of cosmic rays, spanning an area of $17$ km$^2$ with 153 radio antennas, measuring in the energy range around the transition from galactic to extra-galactic origin. It measures the radio emission of extensive air showers produced by cosmic rays, in the $30-80$ MHz band. The cosmic-ray...
High-frequency-peaked BL Lacs (HBLs) dominate the extragalactic TeV sky, with more than 50 objects detected by the current generation of TeV observatories. Still, the properties of TeV-emitting HBLs as a population are poorly understood due to biases introduced by the observing strategies of Cherenkov Telescopes, limiting our ability to estimate the potential contribution of TeV blazars to the...
The Telescope Array experiment is an ultra-high energy cosmic ray observatory located in Millard County, Utah, USA. The observatory consists of 3 fluorescence detector (FD) stations and 507 surface detectors (SD) that cover an area of ~700 km2. Hybrid trigger is an external trigger system for the SD arrays that prompts the SD to perform data acquisition when an FD detects a...
The low flux of ultra-high-energy cosmic rays (UHECRs) makes it challenging to understand their origin and nature. A very large effective aperture is provided by the lunar Askaryan technique. Particle cascades in a dielectric medium produce radio emission through the Askaryan effect. Ground based radio telescopes are used to search for nanosecond radio pulses that are produced when cosmic rays...
The Wavelength-shifting Optical Module, or WOM, is a novel optical sensor that uses wavelength shifting and light guiding to substantially enhance the photosensitive area of UV optical modules. It has been designed for the IceCube Upgrade, a seven-string extension of the IceCube detector planned for the 2023/2024 South Pole deployment season, but its design can be applied to any large particle...
Probing the ultra-high energy cosmic ray (UHECR) spectrum beyond the cutoff at ~40 EeV requires an observatory with an acceptance that is impractical to achieve with ground arrays. We present a concept, designated the Zettavolt Askaryan Polarimeter (ZAP), for radio detection of UHECRs impacting the Moon’s regolith from low-lunar orbit. ZAP would observe several thousands of events above the...
Currently, the Baikal-GVD neutrino telescope consists of 7 clusters of 288 photodetectors. Each cluster is a functionally complete detector which can register events in stand-alone mode and jointly with other clusters. Joint operation of the clusters requires time synchronization with nanosecond accuracy. This paper presents the methods of time synchronization of the clusters, the results of a...
Markarian 501 (Mrk 501) is one of the brightest very high energy (VHE, E> 100 GeV) gamma-ray blazars. It is located in our neighborhood, at redshift z = 0.034. During a multi-wavelength campaign in July 2014, Mrk 501 displayed the highest X-ray activity observed by the Neil Gehrels Swift X-ray telescope (XRT) since its launch. The X-ray spectra displayed during this flaring episode were very...
Time-dependent energy spectra of galactic cosmic rays (GCRs) carry fundamental information regarding their origin and propagation. When observed at the Earth, these spectra are significantly affected by the solar wind and the imbedded solar magnetic field that permeates the heliosphere, changing significantly over an 11-year solar cycle. Energy spectra of GCRs measured during different epochs...
The ARIANNA experiment is a proposed Askaryan detector designed to record radio signals induced by neutrino interactions in the Antarctic ice. Because of the low neutrino flux at high energies, the physics output is limited by statistics. Hence, an increase in sensitivity will significantly improve the interpretation of data and will allow us to probe new parameter spaces. The trigger...
The observation of various cosmic ray particles at the Earth had been done with the PAMELA space detector for almost 10 years, from June 2006 to January 2016. The AMS-02 space experiment provides similar cosmic ray data. The purpose of this work is to utilize the available state-of-the-art numerical modulation model for the transport of cosmic rays in the heliosphere to compute the modulation...
The Askaryan Radio Array (ARA) is a gigaton size neutrino radio telescope located at the near geographic South Pole. ARA has five independent stations designed to detect Askaryan emission coming from the interaction between ultra-high energy neutrinos ( > 10 PeV ) and Antarctic ice. Each station corresponds of 16 antenna clusters deployed in a matrix shape under ~200 m deep in the ice. The...
High-energy neutrinos with energies above a few $10^{16}~$eV can be measured efficiently with in-ice radio detectors which complement optical detectors such as IceCube at higher energies. Several pilot arrays explore the radio technology successfully in Antarctica. Because of the low flux and interaction cross-section of neutrinos it is vital to increase the sensitivity of the radio detector...
Many ultra high energy neutrino detection experiments seek radiowave signals from neutrino interactions deep within polar ice, and an understanding of in-ice radiowave propagation is therefore of critical importance. The parabolic equation (PE) method for modeling the propagation of radio waves is a suitable intermediate between ray tracing and finite-difference time domain (FDTD) methods in...
Phased array radio-frequency (RF) systems have a wide variety of applications in engineering and physics research. Phased array designs are proposed as a trigger system for Askaryan-class in-situ ultra-high energy (UHE) neutrino detectors. Located in Antarctica, these detectors will record RF pulses generated by UHE neutrinos via the Askaryan effect. Modelling the response of phased arrays is...
We describe a radio-frequency polarization measurement by the ARIANNA surface station using a residual hole from the South Pole Ice Core (SPICEcore) Project. Radio pulses were emitted from a transmitter located down to 1.7 km below the snow surface. After deconvolving the raw signals for the detector response and attenuation from propagation through the ice, the signal pulses show no...
We report on the observation of an excess of E>300 TeV gamma-ray candidate events in temporal and spatial coincidence with the IceCube high-energy neutrino alert consistent with the origin in the Cygnus Cocoon. The Cygnus Cocoon is a prospective Galactic source of high-energy neutrinos and photons. The observations have been performed with Carpet-2, a surface air-shower detector equipped with...
The global features of the modulation of galactic cosmic ray protons and helium nuclei are studied in the heliosphere from solar minimum to maximum activity with a comprehensive, three-dimensional, drift model and compared to proton and helium observations measured by PAMELA from 2006 to 2014. Combined with accurate very local interstellar spectra (VLIS) for protons and helium nuclei, this...
The Telescope Array Low energy Extension (TALE) experiment in Utah, U.S.A., consists of 10 atmospheric fluorescence telescopes and 80 Surface Detectors (SDs) spread over an area of 21 $km^2$. The SD array consists of 40 SDs at 400 m spacing and 40 SDs at 600 m spacing. The TALE-SD was completed in February 2018 and has been in steady operation since then, triggering at a rate of about 30 air...
The Telescope Array (TA) cosmic rays detector located in the State of Utah in the United States is the largest ultra high energy cosmic rays detector in the northern hemisphere. The Telescope Array Low Energy Extension (TALE) fluorescence detector (FD) was added to TA in order to lower the detector's energy threshold, and has succeeded in measuring the cosmic rays energy spectrum and mass...
Cost effective in-ice radio detection of neutrinos above a few $10^{16}~$eV has been explored successfully in pilot-arrays. A large radio detector is currently being constructed in Greenland with the potential to measure the first cosmogenic neutrino, and an order-of-magnitude more sensitive detector is being planned with IceCube-Gen2. We present the first end-to-end reconstruction of the...
The Radio Neutrino Observatory Greenland (RNO-G) is planned to be the first large-scale implementation of the in-ice radio detection technique. It targets astrophysical as well as cosmogenic neutrinos with energies above 10 PeV. The deep component of a single RNO-G station consists of three strings with antennas to capture horizontal as well as vertical polarization. This contribution shows a...
The Payload for Ultrahigh Energy Observations (PUEO) is a NASA Long-Duration Balloon Mission that has been selected for concept development. PUEO have unprecedented sensitivity to ultra-high energy neutrinos above 10^18 eV. PUEO will be sensitive to both Askaryan emission from neutrino-induced cascades in Antarctic ice and geomagnetic emission from upward-going air showers that are a result...
The identification of active PeVatrons, hadronic particle accelerators reaching the knee of the cosmic-ray spectrum (at the energy of few PeV), is crucial to understand the origin of cosmic rays in the Galaxy. In this context, we report on new H.E.S.S. observations of the PeVatron candidate HESS J1702-420, which reveal the presence of gamma-rays up to 100 TeV. This is the first time in the...
The in-ice radio detection of the radio signals caused by the interaction of high energy neutrinos in vast natural media like polar ice, will be a promising technique to detect neutrinos of energies beyond the ones thus far measured. Because of the large attenuation length in ice for radio O(1km), sparse arrays can be built implying large effective volumes.
The simulations of effective...
The Non-Imaging CHErenkov Array (NICHE) is a low energy extension to Telescope Array (TA) using an array of closely spaced (~100 m) light collectors covering an area of ~2 square km. It is being deployed in the field-of-view of the FD for the TA Low Energy Extension (TALE) and overlaps with the TALE FD in the energy range above 2 PeV. Cosmic ray air showers with energies 1-100 PeV will be...
We present the energy spectrum of cosmic rays measured at the Pierre Auger Observatory from $6 \times 10^{15}$ eV up to the most extreme energies where the accumulated exposure reaches about 80 000 km$^2$ sr yr. The wide energy range is covered with five different measurements, namely using the events detected by the surface detector with zenith angles below 60 degrees and applying different...
Evolutionary algorithms are a type of artificial intelligence that utilize principles of evolution to efficiently determine solutions to defined problems. These algorithms are particularly powerful at finding solutions that are too complex to solve with traditional techniques and at improving solutions found with simplified methods. The GENETIS collaboration is developing genetic algorithms...
The High-Energy Particle Detector (HEPD) onboard the China Seismo-Electromagnetic Satellite (CSES-01) - launched in February 2018 - is a light and compact payload suitable for measuring electrons (3-100 MeV), protons (30-300 MeV), and light nuclei (up to a few hundreds of MeV) with a high energy resolution and a wide angular acceptance. The very good capabilities in particle detection and...
The Cosmic-Ray Isotope (CRIS) and Solar Isotope Spectrometer (SIS) on the Advanced Composition Explorer(ACE) have measured energy spectra of cosmic-ray elements and isotopes since launch in 1997. We report energy spectra of abundant elements from C to Ni during solar minimum conditions from the 1997, 2009, and 2019-2020 solar minima and compare peak intensities with solar-wind conditions in...
We have been observing cosmic rays and gamma rays above TeV energies with an air shower (AS) array located in Tibet, China at an altitude of 4,300 m and in operation since 1990. In 2014 we added to the air shower array an underground muon detector (MD) array that enables us to observe gamma-ray-induced air showers with far better sensitivity than before, suppressing background cosmic-ray...
The Radio Neutrino Observatory in Greenland (RNO-G) is designed to make the first observations of ultra-high energy neutrinos at energies above 10 PeV, playing a unique role in multi-messenger astrophysics as the world's largest in-ice Askaryan radio detection array. The experiment will be composed of 35 autonomous stations deployed over a 5 x 6 km grid near NSF Summit Station in Greenland....
Recent observations of VER J2227+608 and the associated supernova
remnant G106.3+2.7 by the High Altitude Water Cherenkov (HAWC)
observatory confirm the special interest of this source as a Galactic Pe-
Vatron candidate in the northern hemisphere. HAWC J2227+610 emits
VHE gamma-ray emission, above 100 TeV, from a region coincident with
molecular clouds and shows a hard energy spectrum...
The Askaryan Radio Array (ARA) is a ground-based radio detector at the South Pole designed to capture Askaryan emission from ultra-high energy neutrinos interacting within the Antarctic ice. The newest ARA station has been equipped with a phased array trigger, in which radio signals in multiple antennas are summed in predetermined directions prior to the trigger. In this way, impulsive signals...
An increasing number of experiments are targeting GHz bandwidth impulsive radiation induced by high energy neutrinos in ice or high energy cosmic ray air showers. Beamforming triggers improve detection prospects at low signal-to-noise ratio (SNR), since effective SNR scales as the square root of the number of phased array antennas in a coherent sum. However, this also brings high technological...
The measurement of the energy spectrum of ultra-high-energy cosmic rays (UHECRs) is of crucial importance to clarify their origin and acceleration mechanisms. The Pierre Auger Observatory in Argentina and the Telescope Array (TA) in the US reported their measurements of UHECR energy spectra observed in the southern and northern hemisphere, respectively. The region of the sky accessible to both...
With the construction of RNO-G and plans for IceCube-Gen2, neutrino astronomy at EeV energies is at the horizon for the next years. Here, we determine the neutrino pointing capabilities and explore the sensitivity to the neutrino flavor for an array of shallow radio detector stations. The usage of deep learning for event reconstruction is enabled through recent advances in simulation codes...
We consider in our study the exact two-dimensional (2D) transport equation (TPE) for galactic cosmic ray (GCR) intensity in the heliosphere, averaged over longitude, and derived by averaging the full three-dimensional (3D) steady-state TPE over longitude. As we showed before, this exact 2D TPE is equal to that with the averaged 3D TPE coefficients but with the “source-term” Q2D due to 3D...
The ARIANNA detector is designed to detect neutrinos of energies above $10^{16} eV$. Due to the similarity in generated radio signals, cosmic rays are often used as test beams for neutrino detectors. Some ARIANNA detector stations are equipped with antennas capable of detecting air showers. The radio emission properties of air showers are well understood, and the polarization of the radio...
Interstellar clouds can act as target material for hadronic cosmic rays; gamma-rays produced through inelastic proton-proton collisions and spatially associated with the clouds can provide a key indicator of efficient particle acceleration.
However, even for PeVatron sources reaching PeV energies, the system of cloud and accelerator must fulfil a several conditions in order to produce a...
The compact imaging air-Cherenkov telescope HAWC’s Eye was developed to operate together with the High-Altitude Water Cherenkov Gamma-Ray Observatory (HAWC). The combination of both detection techniques in a hybrid setup provides a significant improvement in energy and angular resolution, aiming for improved measurements of the cosmic ray composition above 10 TeV and contributing to the...
Abstract Imaging Atmospheric Cherenkov telescopes (IACTs) are designed to detect cosmic gamma rays. As a by-product, IACTs detect Cherenkov flashes generated by millions of hadronic air showers every night. We present the proton energy spectrum from several hundred GeV to several hundred TeV, retrieved from the hadron induced showers detected by the MAGIC telescopes. The protons are...
The Telescope Array (TA) is a hybrid cosmic ray detector deployed in 2007 in Millard County, Utah, USA, which consists of a surface detector of 507 plastic scintillation counters spanning a 700 km$^2$ area on the ground that is overlooked by three fluorescence detector stations. The High Resolution Fly's Eye (HiRes) experiment is a predecessor of TA, which consisted of two fluorescence...
The supernova remnant (SNR) G106.3+2.7 is associated with a 100 TeV gamma-ray source reported by HAWC and is thus a promising PeVatron candidate. However, because of the poor angular resolution of HAWC, it is difficult to pinpoint the origin of the 100 TeV source. Because the SNR contains an energetic pulsar wind nebula (PWN) dubbed Boomerang and powered by the pulsar PSR J2229+6114, it is...
The proposed ARIANNA neutrino detector, located at sea-level on the Ross Ice Shelf, Antarctica, consists of 200 autonomous and independent detector stations separated by 1 kilometer in a uniform triangular mesh. The primary science mission of ARIANNA is to search for sources of neutrinos with energies greater than 100 PeV, complementing the reach of IceCube. An ARIANNA observation of a...
Constraining the high energy neutrino flux has been a challenge for decades. IceCube has discovered an astrophysical flux up to 10 PeV and is now planning a large extension with IceCube-Gen2, including an optical array and a large radio array at shallow depth. Neutrino searches for energies >100PeV are best done with such shallow radio detectors like Askaryan Radio Array (ARA) or similar...
The IceCube Neutrino Observatory at the South Pole has measured the diffuse astrophysical neutrino flux up to ~PeV energies and is starting to identify first point source candidates.
The next generation facility, IceCube-Gen2, aims at extending the accessible energy range to EeV in order to measure the continuation of the measured astrophysical spectrum, to identify neutrino sources, and to...
The CALorimetric Electron Telescope (CALET) installed on the International Space Station has multiple event trigger modes for measuring cosmic-ray (CR) particles and gamma rays, and the observations of the low-energy CRs have been successfully performed by a Low-Energy Electron (LEE) shower trigger mode that is active only at high geomagnetic latitude. Continuous measurements of low-energy CRs...
In recent years, several new measurements of the antiproton component of the cosmic radiation have become available. These measurements have improved significantly the existing statistics, extending the explored energy region from few tens of MeV up to hundreds of GeV. These measurements are particularly relevant to understand the propagation of cosmic rays in the Galaxy and in the...
Galactic cosmic rays (GCRs) entering the heliosphere and propagating towards Earth are subject to various modulation processes including drifts, convection, adiabatic energy changes, and diffusion as a result of the turbulent solar wind. This transport can be described by the Parker equation (Parker, 1965). A widely used first-order approximation of the Parker equation is the Force-Field...
The accurate measurements of the galactic cosmic ray (GCR) fluxes as function of time and energy by the Alpha Magnetic Spectrometer (AMS) give us unique information to search dark matter, to study the dynamics of solar modulation, to constraint the parameters in modulation model, to improve the precision of radiation dose prediction in the ongoing deep space exploration.
The transport of low...
The Large High Altitude Air Shower Observatory(LHAASO) is a hybrid extensive air shower(EAS) array with an area of about 1km2 at an altitude of 4410 m a.s.l. in Sichuan province, China. It contains three sub-detectors: 1 km2 array (LHAASO-KM2A) composed of electromagnetic particle (ED) and muon detectors (MD); water Cherenkov detector array(LHAASO-WCDA) and 18 wide field-of-view air Cherenkov...
The Telescope Array (TA) Cosmic Ray Observatory is the largest cosmic ray detector in the northern hemisphere. TA was built to study ultra-high-energy cosmic rays (UHECRs), cosmic rays with energies above 1 EeV. TA is a hybrid detector, employing both a surface detector array and fluorescence telescopes. We present a measurement of the cosmic ray energy spectrum for energies above $10^{17.5}$...
Thanks to recent technological development, a new generation of experiments have been developed with more sensitivity in the energy interval from 10 TeV to 1 PeV, such as HAWC. Due to its designs and high altitude, the HAWC air shower observatory can provide a bridge between the data from direct and indirect cosmic ray detectors. In 2017 the HAWC collaboration published their first results on...
The Askaryan Radio Array (ARA) at the South Pole is designed to detect the radio signals produced by ultra high-energy cosmic neutrino interactions in the ice. There are 5 independent ARA stations, one of which (ARA5) includes a low-threshold phased array trigger string. The Data Acquisition System in all ARA stations is equipped with the Ice Ray Sampler second generation (IRS2) chip, a...
The determination of energy spectrum of different species above 100 TeV is still one of the main challenges in cosmic ray physics. The energy spectrum of the individual component is an important tool to investigate the cosmic ray production and propagation mechanisms. A preliminary results of mixed proton and helium energy spectrum, obtained with the combined data of six Cherenkov telescopes,...
The GRAND project aims to detect ultra-high-energy neutrinos, cosmic rays and gamma rays, with an array of 200,000 radio antennas over 200,000 km2, split into ~20 sub-arrays of ~10,000 km2 deployed worldwide. The strategy of GRAND is to detect air showers above 10^17 eV that are induced by the interaction of ultra-high-energy particles in the atmosphere or in the Earth crust, through its...
We present a pipeline for fast GRB source localization for the Advanced Particle-astrophysics Telescope. APT records multiple Compton scatterings of incoming photons across 20 CsI detector layers, from which we infer the incident angle of each photon's first scattering to localize its source direction to a circle centered on the vector formed by its first two scatterings. Circles from multiple...
The mass composition is one of the key information to understand the origin of ultra-high energy cosmic rays. The interpretations of the mass composition from results by air shower experiments depend on hadronic interaction models used for the simulation. The uncertainties due to interaction models are reduced using recent experimental results at LHC.
However, due to no experimental results...
The Pierre Auger Observatory has a large exposure to search for upward propagating shower-like events, and we have used 14 years of its Fluorescence Detector (FD) data to perform a generic search for such events. Recent observations of two coherent radio pulses with the ANITA detector are consistent with steeply upward-going cosmic-ray showers with energies of few tenths of an EeV and remain...
In light of the most recent observations of late afterglows produced by the merger of compact objects or by the core-collapse of massive dying stars, we research the evolution of the afterglow produced by an off-axis top-hat jet and its interaction with a surrounding medium. The medium is parametrized by a power law distribution of the form $n(r)\propto r^{-k}$, where $k$ is the stratification...
Interplanetary coronal mass ejections (ICMEs) cause decreases, so-called Forbush decreases, in the cosmic ray (CR) intensities. FDs are seen as up to 25% decreases in neutron monitor counts at Earth, lasting up to over a week. An ICME is thought to cause a FD through two mechanisms: by enhancing diffusion in the ICME shock wave sheath; and by preventing the CRs from penetrating the magnetic...
'We present a new method to explore simple ad-hoc adjustments to the predictions of hadronic interaction models to improve their consistency with observed two-dimensional distributions of the depth of shower maximum, Xmax, and signal at ground level, as a function of zenith angle. The method relies on the assumption that the mass composition is the same at all zenith angles, while the...
Measurements of the muon content of extensive air showers at the highest energies show discrepancies compared to simulations as large as the differences between proton and iron. This so-called muon puzzle is commonly attributed to a lack of understanding of the hadronic interactions in the shower development. Furthermore, measurements of the fluctuations of muon numbers suggest that the...
The ANITA collaboration has recently reported on four anomalous cosmic-ray-like events observed during ANITA's fourth flight that are observationally consistent with air showers from upgoing particles emerging from the Antarctic ice. One possible interpretation of these events is that they are due to ultrahigh energy tau neutrinos interacting in the Earth, resulting in an extensive air shower...
Relativistic hadronic plasmas have an intriguing property known as hadronic supercriticality: they can, under certain conditions, abruptly and efficiently release the energy stored in protons through photon outbursts. These photon flares may have a direct analogy to those observed from compact astrophysical objects, such as Gamma Ray Bursts (GRBs). Here, we investigate for the first time the...
The Cosmic Ray Energetics And Mass for the International Space Station (ISS-CREAM) experiment successfully recorded the data for about 539 days from August 2017 to February 2019. In this talk, we report the measurement of the cosmic-ray proton energy spectrum from the ISS-CREAM experiment in the energy range of 2.5 TeV−650 TeV. For the analysis, we used the silicon charge detector (SCD) placed...
We present the results of an analysis of on-orbit data from the Cosmic Ray Energetics And Mass instrument for the International Space Station. The design objective is to measure the elemental spectra of cosmic rays from Z=1 to Z=26 over the energy range of $10^{12} - 10^{15}$ eV. The instrument was installed on the ISS on August 22, 2017 with operations terminated on February 12, 2019,...
Pieter Kotzé
Space Physics, North-West University, Potchefstroom, South Africa
Periodicities in galactic cosmic particles like C, N, O and Fe as observed by the ACE satellite between 2000 and 2019 have been analyzed using various spectral analysis techniques. Daily mean energetic particle measurements are used to identify how several harmonics of the ~ 27-day synodic rotation period change...
In heavy ion collisions, the main goal is to create the quark-gluon plasma (QGP) and then study its properties in order to understand quantum chromodynamics at extreme conditions. Collective flow serves as an important probe to study the production and characterize the property of the QGP. In ultra high energy cosmic rays (UHECR), the collision energies are an order of magnitude higher than...
DAMPE (DArk Matter Particle Explorer) is a Space mission project promoted by the Chinese Academy of Sciences (CAS), in collaboration with Universities and Institutes from China, Italy and Switzerland. The satellite hosting the DAMPE detector has been successfully launched on December 17th, 2015, and is currently collecting data in a stable way. The main goals of the mission are: indirect...
Cosmic Ray Energetic And Mass for the International Space Station (ISS-CREAM) was designed to study high-energy cosmic-rays on the ISS. The ISS-CREAM instrument can measure high energy cosmic rays up to PeV energies and recorded data from August 22nd, 2017 to February 12th, 2019. In this analysis, the silicon charge detector (SCD), calorimeter (CAL) and top and bottom counting detectors...
We present a measurement of the density of GeV muons in near-vertical air showers using three years of data recorded by the IceTop array at the South Pole. We derive the muon densities as functions of energy at reference distances of 600 m and 800 m for primary energies between 2.5 PeV and 40 PeV and between 9 PeV and 120 PeV, respectively. The measurements are consistent with the predicted...
Around 11.4 million years ago a young, highly magnetized neutron star, a magnetar, in the Sculptor galaxy released an enormous amount of energy in the form of a giant flare. On April 15$^{\rm th}$ 2020 some of the emitted photons were detected by a number of gamma-ray telescopes around Earth and Mars. While the analysis of this event, GRB 200415A, was...
Dark Matter Particle Explorer（DAMPE) is a calorimetric-type, satellite-borne detector for observations of high energy electrons, gamma-rays, and cosmic-ray nuclei. Using five years data recorded with DAMPE from January 1, 2016 to December 31, 2020, we measure the spectrum of iron nuclei in a wide energy range. Detailed studies of the fragmentation of iron in the detector have been performed...
Multi-messenger observations of transient astrophysical sources have the potential to characterize the highest energy accelerators and the most extreme energy environments in the Universe. Detection of neutrinos, in particular tau neutrinos generated by neutrino oscillations in transit from their sources to Earth, is possible for neutrino energies above 10 PeV using optical Cherenkov detectors...
Solar energetic particles (SEPs) and Forbush decreases (Fds) in galactic cosmic ray (GCR) intensity are two important phenomena accompanied by interplanetary coronal mass ejections (ICMEs). A fast and strong magnetic cloud (MC) was behind the ICME-driven shock associated with the ground-level enhancement event on 2000 July 14. Observations show that both SEPs and GCRs had a rapid two-step...
We present the measurements of the energy spectra of carbon and oxygen nuclei in cosmic rays based on 4 years of observation with the Calorimetric Electron Telescope (CALET) on the International Space Station. The energy spectra are measured from 10 GeV/n to 2.2 TeV/n with an all calorimetric instrument with a total thickness corresponding to 1.3 nuclear interaction length and equipped with...
Characteristics of muons with a threshold $\varepsilon_{thr} \geq$ 1 GeV based on the air showers data in Yakutsk array were analyzed. Quantitative estimation of muons at different distance from the shower axis and the ratio of muon and charged particles at a distance of 600 m are obtained. An empirical relationship between the fraction of muons and longitudinal development – the depth of...
Measurements of KASCADE-Grande on the muon size in high energy extensive air showers (EAS) have provided evidence that the actual attenuation length of shower muons in the atmosphere is larger than the expectations from the hadronic interaction models QGSJET-II-04, EPOS-LHC and SIBYLL 2.3. This discrepancy is related to a deficient description of the shower muon content with atmospheric depth...
Calorimetric Electron Telescope (CALET) is aiming to measure the main components of high energy cosmic rays up to ~1 PeV in order to understand the cosmic ray acceleration and propagation. The detector consisting of a charge detector, an imaging calorimeter, and a total absorption calorimeter, is located on the International Space Station. The thickness of the calorimeter corresponds to 30...
Solar activity was intense in September 2017 and its effects were observed in detectors placed in the Earth's surface. Three halo Coronal Mass Ejections (CME) hit the planet and caused magnetic storms. The effects of the CMEs on the flux of galactic cosmic rays at ground level were observed by the Tanca detector, which is one of the water-Cherenkov detectors (WCD) that make up the Latin...
Fast radio burst (FRBs) are an exciting class of bright, extragalactic, millisecond radio transients. The recent development of large FOV radio telescopes has caused a rapid rise in the number of identified single burst and repeating FRBs. This has allowed for extensive multi-wavelength follow-ups to search for the potential counterparts predicted by theoretical models. New observations of...
Gamma-ray bursts (GRBs) are the most powerful outbursts of electromagnetic radiation in our Universe. A subset of GRBs are accompanied by precursors, dim gamma-ray flashes that precede the main outburst by tens to hundreds of seconds. We present an analysis of 11 years of Fermi-GBM data to identify these precursor flashes. For each of the 2364 analyzed GRBs, a time window of 2000 s centered on...
Despite over 50 years of observations of Gamma-Ray Bursts (GRBs) many open questions remain about their nature and their environments in which the emission takes place. Polarization measurements of the GRB prompt emission have long been theorized to be able to answer most of these questions. The POLAR detector was a dedicated GRB polarimeter developed by a Swiss, Chinese and Polish...
We present characteristics of hadronic cascades from interactions of cosmic rays in the atmosphere, simulated by the novel CORSIKA 8 framework. The simulated spectra of secondaries, such as pions, kaons, baryons and muons, are compared with cascade equations solvers CONEX and MCEq in air shower mode and full 3D air shower Monte Carlo simulations using the legacy CORSIKA 7 and AIRES. A novel...
Hypernova remnants (HNRs) and magnetar wind nebulae (MWNe), supported by new-born millisecond magnetars, as well as magnetar giant flares are promising PeVatron candidates and even potential sources of ultra high energy cosmic rays (UHECRs, E>10^{18} eV). Nonthermal high-energy (HE, E>100 MeV) and very high-energy (VHE, E>100 GeV) γ-ray emission from magnetars' outskirts should be an...
Nowadays the implementation of artificial neural networks in high-energy physics has obtained excellent results on improving signal detection. In this work we propose to use neural networks (NNs) for event discrimination in HAWC. This observatory is a water Cherenkov gamma-ray detector that in recent years has implemented algorithms to identify horizontal muon tracks. However, these algorithms...
Fast radio bursts (FRBs) are one of the most exciting new mysteries of astrophysics. Their origin is still unknown, but recent observations seems to link them to Soft Gamma Repeaters and, in particular, to magnetar giant flares (MGFs). The recent detection of a MGF at GeV energies by the Fermi Large Area Telescope (LAT) motivated the search for GeV counterparts to the >100 currently known...
The search for ultra-high energy neutrinos is more than half a century old. While the hunt for these neutrinos has led to major leaps in neutrino physics, including the detection of astrophysical neutrinos, neutrinos at the EeV energy scale remain undetected. Proposed strategies for the future have mostly been focused on direct detection of the first neutrino interaction, or the decay shower...
During LHC runs 1-2 the LHCf experiment measured neutral particles in the forward region of proton+proton and proton+lead ion collisions. These measurements allow the testing and fine tuning of hadronic interaction models in a phase space region relevant for studying the development of cosmic-ray air showers. One of the limitations in using the results obtained so far by LHCf is linked to the...
Magnetar giant flares (MGFs) are enormous eruptions likely triggered by surface disruptions in magnetars, neutron stars with the strongest-known magnetic fields. Such events can be detected in both X- and gamma-ray bands, but are very rare. Almost 30 magnetars have been cataloged in our Galaxy, exhibiting occasional X-ray activity, but only two have produced giant flares to date. The most...
Direct measurements of cosmic-rays (CRs) is fundamental to achieve a better understanding of their origin, mechanism of acceleration and propagation in the Galaxy. Due to the hardening around a few hundred GeV/n in the spectrum of proton, helium and heavy nuclei from recent observations, it is of great importance to provide new and precise measurements of the region of transition for each...
The number of muons observed at the ground from air showers is sensitive to the mass composition of cosmic ray. Large High Altitude Air Shower Observatory is a hybrid extensive air shower array and the KM2A is a sub-array covering an area of 1 km$^2$, consisting of electromagnetic detectors and muon detectors, can measure the muon content and shower size of the air shower simultaneously with...
The CALorimetric Electron Telescope (CALET) is a space instrument designed to carry out precision measurements of high energy cosmic-rays.
It was installed onboard the International Space Station in August 2015 and since mid-October 2015 it is collecting data with excellent performance and no significant interruptions.
The instrument consists of two layers of segmented plastic scintillators...
The Calorimetric Electron Telescope (CALET), in operation on the International Space Station since 2015, has collected a large sample of cosmic-ray charged particles and gamma-rays over a wide energy interval. The instrument consists of two layers of segmented plastic scintillators to identify the charge of individual elements from proton to iron (and above), a thin imaging tungsten...
The DArk Matter Particle Explorer (DAMPE) is a space-based particle detector launched in a Sun-synchronous orbit on December 17th, 2015 from the Jiuquan Satellite Launch Center, in China. It is taking data very smoothly since more than 5 years. Science goals of the DAMPE mission include the study of the electron-positron energy spectrum, the study of galactic cosmic-rays, gamma-ray astronomy,...
Ultra High Energy Cosmic Ray (UHECR) detectors have been reporting on the proton-air cross section measurement beyond the capability of particle accelerators since 1984. The knowledge of this fundamental particle property is vital for our understanding of high energy particle interactions and could possibly hold the key to new physics. The data used in this work was collected over eight years...
One of the first setups at which an excess of muons in comparison with the expectation (“muon puzzle”) was detected and its dependence on the primary energy was measured, was the NEVOD-DECOR complex. Since various mechanisms for the appearance of an excess of multi-muon events (of cosmophysical or nuclear-physical nature) should have different effects on the muon energy, one of the possible...
Cosmic ray muons arise from the showers of secondary particles produced in the interactions of primary cosmic particles with air nuclei at the top of the atmosphere. The interaction products, pions and kaons composing showers mostly decay to muons reflect the details of the hadronic interactions depending on their energy. Measurements of the charge ratio and polarization of cosmic ray muons...
The development of hadronic cascades in extensive air-showers is modeled by hadronic interaction models based on extrapolations of collider data. The models' predictions at the highest energies are at a known tension with the description of measurements of the muonic component if the mass composition derived from the fluorescence technique is assumed. We apply an ad-hoc modification to the...
The Galactic magnetar SGR 1935+2154 was associated with a bright, millisecond-timescale fast radio burst (FRB) which occurred in April 2020, during a flaring episode. This was the first time an FRB was unequivocally associated with a Galactic source, and the first FRB for which the nature of the emitting source was identified. Moreover, it was the first FRB with a counterpart at another...
An accurate modeling of neutrino flux attenuation and the distribution of leptons they produce in transit through the Earth is an essential component to determine neutrino flux sensitivities of underground, sub-orbital and space-based detectors. Through neutrino oscillations over cosmic distances, astrophysical neutrino sources are expected to produce nearly equal fluxes of electron, muon and...
Multiple experiments reported evidences of a muon deficit in air-shower simulations with respect to data, which increases with the primary energy. In this work, we study the muon deficit using measurements of the muon density at $1000\,$m from the shower axis obtained by the Akeno Giant Air Shower Array (AGASA). The selected events have reconstructed energies in the range...
Data of the NEVOD-DECOR experiment on investigations of inclined cosmic ray muon bundles for a long time period (May 2012 – March 2021) are presented. Their comparison with the results of calculations based on simulations of EAS hadron and muon components allows one to study the behavior of the energy spectrum and mass composition of primary cosmic rays and/or to check the validity of hadron...
The number of muons in extensive air showers predicted using LHC-tuned hadronic interaction models, such as EPOS-LHC and QGSJetII-04, is smaller than observed in showers recorded by leading cosmic rays experiments. In this paper, we present a new method to derive muon rescaling factors by analyzing reconstructions of simulated showers. The z-variable used (difference of initially ...
Neutrinos are invisible, but their interactions with matter and their leptons signature leave an observable trace. Because the huge atmospheric neutrino noise, produced by cosmic ray rain, there is much hope for reveal highest energy neutrino as an astronomy, above TeVs energy. Neutrino and antineutrino are three. Electron traces radiate a lot therefore are short (meters) trace inside...
A Corotating Interaction Region (CIR) is formed when the fast solar wind catches the slow solar wind. It is known that the intensity of Galactic Cosmic Ray (GCR) is modulated by the CIR. Usually, the GCR intensity is suppressed inside the CIR. However, previous studies were mainly confined to GCR protons. In this study, we have utilized a hybrid GCR transport model, which incorporates the...
nuSpaceSim is a comprehensive end-to-end simulation package to model the optical and radio signals from extensive air showers (EAS) induced by cosmic neutrino interactions. The development has initially focused on modeling the upward-moving EASs sourced from tau neutrino interactions within the Earth that employs a new modeling package, nuPyProp. nuSpaceSim is designed to model all aspects of...
Fast radio bursts (FRB) are enigmatic powerful single radio pulses with durations of several milliseconds and high brightness temperatures suggesting coherent emission mechanism. For the time being a number of extragalactic FRBs have been detected in the high-frequency radio band including repeating ones. The most plausible explanation for these phenomena is magnetar hyperflares. The first...
Recently, several experiments reported a muon deficit in air-shower simulations with respect to the data. This problem can be studied using an estimator that quantifies the relative muon content of the data with respect to those of proton and iron Monte-Carlo air-shower simulations. We analyze two estimators. The first one, based on the logarithm of the mean of the muon content, is built from...
Astrophysical Ultra-High Energy (UHE) neutrinos probe the accelerators of Ultra-High Energy Cosmic Rays (UHECR), the composition of UHECR, and neutrino physics at the highest energies. UHE-tau neutrinos (E > 10 PeV) skimming the Earth produce tau leptons which can emerge from the ground, decay, and initiate an upward-going particle shower in the atmosphere. By measuring the Cherenkov emission...
We study the periodic variations of GCRs related to solar rotation based on neutron monitor, ACE/CRIS, STEREO and SOHO/EPHIN measurements. Now there is an opportunity to re-analyze the polarity dependence of the amplitudes of the recurrent GCR variations in 2007-2009 for negative A < 0 polarity and in 2017-2019 for A > 0. We use the Fourier analysis method to study the periodicity in the GCR...
Neutron monitor cosmic rays and Sun Spot Number (SSN) measurements from 1964 to 2019 corresponding with the Solar Cycles 20–24 have been used. A Global Neutron Monitor (GNM) has been built as virtual representative station to characterize solar activity. Morlet wavelet analysis was applied to the GNM and SSN in order to determine possible periodicities. This analysis was applied both to
the...
The detailed measurement of the daily proton fluxes from May 20, 2011 to October 29, 2019 with the Alpha Magnetic Spectrometer on the International Space Station, is presented. We observed that the proton fluxes exhibit daily, monthly, and yearly variations. Beginning from 2015, we observed periodicities of 27, 13.5, and 9 days. The rigidity dependence of these periodicities is presented.
We report the properties of aluminum (Al) cosmic rays in the rigidity range 2.15 GV to 3.0 TV with 0.51 million nuclei collected by the Alpha Magnetic Spectrometer experiment on the International Space Station. We observed that above 6 GV the Al flux is well described by the weighted sum of the silicon flux (primary cosmic rays) and the fluorine flux (secondary cosmic rays). The fraction of...
We report the properties of sodium (Na) cosmic rays in the rigidity range 2.15 GV to 3.0 TV with 0.46 million nuclei collected by the Alpha Magnetic Spectrometer experiment on the International Space Station. We observed that above 6 GV the Na flux is well described by the weighted sum of the silicon flux (primary cosmic rays) and the fluorine flux (secondary cosmic rays).
The fraction of...
We report the observation of new properties of primary iron (Fe) cosmic rays in the rigidity range 2.65 GV to 3.0 TV with 0.62 million iron nuclei collected by the Alpha Magnetic Spectrometer experiment on the International Space Station. Above 80.5 GV the rigidity dependence of the cosmic ray Fe flux is identical to the rigidity dependence of the primary cosmic ray He, C, and O fluxes, with...
We report the observation of new properties of primary cosmic rays, neon (Ne), magnesium (Mg), and silicon (Si), measured in the rigidity range 2.15 GV to 3.0 TV with 1.8 million Ne, 2.2 million Mg, and 1.6 million Si nuclei collected by the Alpha Magnetic Spectrometer experiment on the International Space Station. The Ne and Mg spectra have identical rigidity dependence above 3.65 GV. The...
Several types of Galactic sources, like magnetars, microquasars, novae or pulsar wind nebulae flares, display transient emission in the X-ray band. Some of these sources have also shown emission at MeV and even at few GeV energies, although none of these Galactic transients have ever been detected in the very-high-energy (VHE; E>100 GeV) regime by any Imaging Air Cherenkov Telescope...
Tau neutrinos interacting in the Earth can result in upgoing extensive air showers. These showers produce optical and radio emission that can be detected by orbital and suborbital platforms. As part of NASA’s nuSpaceSim program, to develop a comprehensive end-to-end simulation package to model these signals, we present results of radio emission simulations using ZHAireS for observation from...
The Cosmic Ray Energetics And Mass for the International Space Station (ISS-CREAM) experiment took high energy cosmic ray data for 539 days after its successful installation
on the ISS in August 2017. The ISS-CREAM instrument is configured with complementary
particle detectors capable of measuring elemental spectra for Z = 1 - 26 nuclei in the energy
range 1012 – 1015...
We present the results of a search for upward-going showers using the Fluorescence Detector (FD) of the Pierre Auger Observatory. Upward-going air showers are a possible interpretation of the recent events reported by the ANITA Collaboration in the energy range above $10^{17}$ eV. Given its operation time and wide field of view, the FD is sufficiently sensitive to upward-going events and can...
Since the detection of Gravitational Waves (GW), a new window of multi-messenger astronomy was opened. The first GW event with an electromagnetic counterpart was GRB 170817A, an under luminous burst with properties of a short burst that was detected by Fermi-GBM, among other observatories. This burst revealed two different spectral components in the GBM energy range, a short-lasting...
The Beamforming Elevated Array for COsmic Neutrinos (BEACON) is a concept for a neutrino telescope designed to measure tau lepton air showers generated from tau neutrino interactions near the horizon. This detection mechanism provides a pure measurement of the tau flavor of cosmogenic neutrinos, which could be used to set limits on the observed flavor ratios for cosmogenic neutrinos in a...
Precise understanding of hadronic interactions at high energies is a key to improve chemical composition measurements of very high energy cosmic-rays and to solve the muon excess issue observed in high energy cosmic-ray experiments using air-shower technique. The LHCf and RHICf experiments measures the differential production cross sections of very forward neutral particle as photons, neutral...
The mass composition is one of the key observables to understand the nature and origin of ultrahigh-energy cosmic rays (UHECRs). The study of hadronic interactions at energies well beyond human-made accelerators is a fundamental probe of elementary particle physics. In previous analyses, the properties of the hadronic interactions were estimated under the assumption of a certain mass...
In the sub-TeV regime, the most widely used hadronic interaction models disagree significantly in their predictions for post-first interaction and ground-level particle spectra from cosmic ray induced air showers. These differences generate an important source of systematic uncertainty in their experimental use. We investigate the nature and impact of model uncertainties through a...
Very-High-Energy (VHE) neutrinos are expected to be produced by cosmic-ray interactions with the Cosmic Microwave Background (CMB). In these photo-hadronic interactions, muon- and electron-neutrinos are produced. As these neutrinos traverse the cosmic void, they morph from one flavor to another, yielding, in the standard scenario, a democratic flavor composition at their arrival on Earth. This...
The IceCube Neutrino Observatory, with its deep in-ice detector IceCube and surface array IceTop, provides the unique possibility to measure the low-energy (∼1 GeV) and high-energy (>500 GeV) muon component as well as the electromagnetic component of cosmic-ray air showers simultaneously. For events coincident between the two detectors, IceTop provides an estimate of the primary cosmic-ray...
The ultrahigh-energy (UHE; > 10^6 GeV) neutrinos band is one of the last unopened windows to the universe. Although UHE neutrinos are not yet detected, we know they must exist. UHE neutrinos are either produced in interactions of ultrahigh-energy cosmic rays with the cosmic microwave background (cosmic neutrinos) or inside or close by cosmic-ray accelerators. This presentation discusses the...
Using neutron time-delay data from neutron monitors (NMs), we can extract the leader fraction, L, of neutron counts that do not follow a previous neutron count in the same counter tube due to the cosmic ray shower. L is the inverse of the neutron multiplicity and serves as a proxy of the cosmic ray spectral index over the rigidity range of the NM response function. We have outfitted...
Earth-skimming neutrinos are those which travel through the Earth’s crust at a shallow angle. For Ultra-High-Energy (E$_\nu$ > 1 PeV; UHE) earth-skimming tau neutrinos, there is a high-probability that the tau particle created by a neutrino-Earth interaction will emerge from the ground before it decays. When this happens, the decaying tau particle initiates an air shower of relativistic...
Over the last two decades, various experiments have measured muon densities in extensive air showers over several orders of magnitude in primary energy. While some experiments observed differences in the muon densities between simulated and experimentally measured air showers, others reported no discrepancies. We will present an update of the meta-analysis of muon measurements from nine air...
The LHCf experiment, situated at the LHC accelerator, is composed of two independent detectors located at 140 metres from the ATLAS interaction point (IP1) on opposite sides along the beam axis. LHCf covers the pseudorapidity region above 8.4, with the capability to measure zero-degree neutral particles. The physics motivation of the experiment is to test the hadronic interaction models...
We have used COSIKA to study, through air-shower simulations, observational signatures of a possible increase in cross-section and multiplicity in collisions with center-of-mass energies exceeding $\sim$ 50 TeV. We have simulated collisions for primaries with energies in the range $10^8 - 10^{12}$ GeV. We have used two different high energy models for the simulations, EPOS LHC and...
The deficit of muons in the simulation of extensive air showers is a long-standing problem and the origin of large uncertainties in the reconstruction of the mass of the high energy primary cosmic rays. Hadronic interaction models, re-tuned after early LHC data, have a more consistent description of the muon content among them but still disagree with data. Collective hadronization due to the...
Cosmic-ray-driven instabilities play a decisive role during particle acceleration at shocks and CR propagation in galaxies and galaxy clusters. These instabilities amplify magnetic fields and modulate CR transport so that the intrinsically collisionless CR population is tightly coupled to the thermal plasma and provides dynamical feedback. Here, we show that CRs with a finite pitch angle drive...
We report a study on the conversion of a giant cosmic ray observatory for air shower observation to observe cosmic ray intensity variations caused by solar activity, anisotropy associated with interplanetary disturbances, and detection of sudden cosmic ray events on the earth's surface. In this report, we use data from the surface detectors operated by the Telescope Array experiment located at...
Analysis of anisotropy of the arrival directions of galactic protons, helium, carbon and oxygen has been performed with the Alpha Magnetic Spectrometer on the International Space Station. These results allow to investigate the origin of the spectral hardening observed by AMS in these cosmic ray species. The AMS results on the dipole anisotropy are presented along with the discussion of the...
The Telescope Array (TA) experiment is located in the western desert of Utah, USA and observes ultra-high energy cosmic rays in the northern hemisphere. At the energies, the shape of the cosmic ray energy spectrum carries information of the source distribution. We present the search for differences in spectrum shape in different parts of the sky using latest data of TA surface detector (SD)...
Blazars are characterized by flux variability that is frequency-dependent and manifests in a variety of timescales. Decade-long monitoring of blazars at optical and infrared (OIR) wavelengths with the Small and Moderate Aperture Research Telescope System (SMARTS) in Chile and in gamma-rays with the Fermi Large Area Telescope (LAT) has enabled the systematic study of their multi-wavelength...
Several models have been suggested to explain the fast gamma-ray variability observed in blazars, but its origin is still debated. One scenario is magnetic reconnection, a process that can efficiently convert magnetic energy to energy of relativistic particles accelerated in the reconnection layer. In our study, we compare results from state-of-the-art particle-in-cell simulations with...
Star formation proceeds inefficiently in galaxies for reasons that remain under debate. In the local ISM it is known that the cosmic rays (CRs) provide a significant fraction of total ISM pressure and therefore contribute to hydrostatic balance. I will set out a model for the dynamical effect of CRs, directly accelerated as a result of star formation itself, on the ISM gas column. On the basis...
In the standard picture of cosmic ray transport the propagation of charged cosmic rays through turbulent magnetic fields is described as a random walk with cosmic rays scattering on magnetic field turbulence. This is in good agreement with the highly isotropic arrival directions as this diffusion process effectively isotropizes the cosmic ray distribution. However, high-statistics...
The bulk propagation speed of GeV-energy cosmic rays is limited by frequent scattering off hydromagnetic waves, predominantly by waves that they generate themselves through a resonant streaming instability. In most simulations of galaxy evolution, cosmic rays are then assumed to be strongly coupled to the gas; however, when we zoom into the multiphase, frequently under-resolved ISM, we find a...
Galactic winds can alter the evolution of a disk galaxy by launching outflows from the disk that move gas into the circumgalactic medium (CGM) so that the gas is unavailable to star formation while slowing the infall of fresh gas onto the disk. One agent that is able to drive these galactic winds are GeV cosmic rays (CR) injected by supernovae into the intersellar medium. Through a...
We investigate the damping of Alfvén waves generated by the
cosmic ray resonant streaming instability as due to ion-neutral
damping, turbulent damping and non linear Landau damping, in the
warm ionised and warm neutral phases of the interstellar medium.
We do so in the context of the cosmic ray escape and propagation
in the proximity of supernova remnants. For the ion-neutral...
Telescope Array (TA) and Auger experiments reported anisotropies in the arrival direction of ultra-high-energy cosmic rays (UHECRs). In particular, Auger reported a correlation between UHECR events and the flux model of assumed sources, and suggested a contribution of starburst galaxies (SBGs) to the anisotropy of UHECRs. However, they did not take into account the effect of coherent...
Molecular clouds are complex magnetised structures, with variations over a broad range of length scales. Ionisation in dense, shielded clumps and cores of molecular clouds is thought to be caused by charged cosmic rays (CRs). These CRs can also contribute to heating the gas deep within molecular clouds, and their effect can be substantial when CRs are abundant. CR propagation is predominantly...
The First G-APD Cherenkov Telescope (FACT) has been monitoring blazars at TeV energies for more than eight years. Using solid state photo sensors and performing robotic operations results in a maximized duty cycle of the instrument and minimized observational gaps, providing an unprecedented data sample of more than 14700 hours of physics data. With an unbiased observing strategy, a small...
I will review the applications, advantages, limitations, and current status of harmonic techniques to detect anisotropies in the UHECR arrival direction distribution. In particular I will focus on the harmonic cross-correlation between the UHECR sky and galaxies, where the latter are taken as proxies for the locations of UHECR sources in the assumption that such sources correlate with the...
Since starting full operations, the HAWC gamma-ray observatory has detected and monitored the high-energy TeV emission of the nearby BL Lac objects Markarian 421 and Markarian 501. HAWC performed a follow-up survey of Active Galactic Nuclei selected from the 3FHL Fermi Catalog covering 60% of the sky and up to redshift z<0.3. Using over 4.5 years of HAWC data we found low-significance evidence...
The Telescope Array (TA) experiment, the largest studying ultrahigh energy cosmic rays in the northern hemisphere, has reported an excess in the arrival direction distribution for events with energies above $5.7\times10^{19}$ eV, called the hotspot. We report here the latest results of the TA hotspot using the most recent data measured by the TA surface detector array, which is more than...
The majority of the active galactic nuclei detected at very-high-energies above 100 GeV belong to the class of blazars with a small angle between the jet-axis and the line-of-sight. Only about 10 percent of the gamma-ray AGN are objects with a larger viewing angle resulting in a smaller Doppler boosting of the emission. Originally, it was believed that gamma-ray emission can only be observed...
More than half a century after the discovery of ultra-high energy cosmic rays (UHECRs), their origin is still an open question. The study of anisotropies in the arrival directions of such particles is an essential ingredient to solve this puzzle. We update our previous analysis of large-scale anisotropies observed by the Pierre Auger Observatory using the latest data collected before the...
The deflection of cosmic rays (CRs) in the interstellar magnetic field results in an almost isotropic flux as observed on Earth. However, an anisotropy has been observed at the level of $\sim 10^{−4} − 10^{−3}$. The GRAPES-3 experiment located at Ooty, India consists of an array of 400 plastic scintillator detectors. It measures the particle densities and their relative arrival times in...
The dipole anisotropy of multi-TeV cosmic rays exhibits a strong energy dependence that is at odds with the predictions of standard isotropic diffusion models. It has been argued that the observed variation in amplitude and phase is a consequence of the global distribution of cosmic ray sources in combination with anisotropic diffusion in our local environment. For a quantitative...
The measurement of an astrophysical flux of high-energy neutrinos by IceCube is an important step towards finding the long-sought sources of cosmic rays. Nevertheless, the long exposure neutrino sky map shows no significant indication of point sources so far. The real-time follow-up of neutrino events turned out to be the most successful approach in neutrino point-source searches. It brought,...
Blazars, together with other active galactic nuclei, are the most luminous persistent sources in our universe; and therefore a prime candidate for very-high-energy (>0.2 TeV, VHE) gamma-ray observations. For the two MAGIC telescopes, the Mrk501 galaxy is among the brightest observed blazars due to its proximity.
We report a multi-wavelength and multi-messenger study of Mrk501 with data from...
The blazar Mrk 421 shows frequent, short outbursts in the TeV energy regime.
Due to the fast nature of such episodes, we often fail to obtain sufficient simultaneous information about flux variations in several energy bands. To overcome this lack of multi-wavelength (MWL) coverage, especially for the pre- and post-flare periods, we began a program to monitor the object with the FACT (TeV...
QSO B0218+357 is currently the only gravitationally lensed source from which very-high-energy (VHE,>~100GeV) gamma-ray emission has been detected. We report the multiwavelength monitoring observations of this source performed between 2016 and 2020 in radio interferometry, optical, X-ray and gamma-ray bands. During the monitoring individual flares in optical, X-ray and GeV bands have been...
Flux of muon component of secondary cosmic rays is affected by varying conditions in the atmosphere. Dominant effects are barometric and temperature effect which reflect variations of atmospheric pressure and atmospheric temperature respectively. Precise modeling and correction for these meteorological effects significantly increases sensitivity of Earth-based muon detectors to variations of...
The complete IceCube Observatory has collected over 577 billion cosmic-ray induced muon events from May 2011 to May 2020. We used this data set to provide an unprecedented statistically accurate map of the cosmic ray arrival direction distribution in the TeV-PeV energy range scale in the southern hemisphere. Such an increase in event statistics makes it possible to extend the sensitivity to...
A global large-scale anisotropy in the arrival directions of cosmic rays were observed both in the Northern and Southern Hemisphere. Above 100 TeV, change in the morphology of the arrival direction distribution is appeared. However, most reports of anisotropy are from TeV to hundred TeV and only a few experiments can up to PeV with long term data accumulation. The measurement of anisotropy at...
The acceleration of non-thermal particles in collisionless shocks, especially in supernova remnant shocks, is a long standing problem for revealing the origin of Galactic cosmic-rays. In the most relied scenario, the Galactic cosmic-rays originate in the diffusive shock acceleration mechanism, and the pressure of accelerated cosmic-rays should be large comparable to the ram pressure of...
VERITAS is one of the world’s most sensitive detectors of astrophysical very high energy (VHE; E > 100 GeV) gamma rays. This observatory has operated for ~14 years, and nearly 7,000 hours of its observations have been targeted on active galactic nuclei (AGN). Approximately 300 AGN were observed with VERITAS, and 40 are detected. These studies are generally accompanied by contemporaneous,...
The high-synchrotron-peaked blazars Markarian 421 and Markarian 501 are close bright and well-studied active galactic nuclei, which feature persistent GeV and TeV emission. FACT and Fermi-LAT have been monitoring these two sources providing the densest long-term dataset of unbiased gamma ray observations. Light curves in the TeV and GeV energy bands, spanning over a five-year period, were used...
We studied the evolution of the solar neutron flux in the Earth’s atmosphere. Simulations based on the CORSIKA and FLUKA codes were performed for this purpose. We analyzed the neutron (n) emission of three flares (X17, M3.9 and X1.3), observed by the Solar Neutron Telescope at Sierra Negra (SNT-SN) and the FIB scintillator of the Space Environment Data Acquisition-Attached Payload (FIB...
We calculate the shape of the TeV-PeV cosmic-ray anisotropy (CRA) in 3D Kolmogorov turbulence. We present the first numerical calculations of the CRA down to TeV energies, using realistic values for the coherence length of the interstellar turbulence. At these low energies, the large-scale CRA aligns with the direction of local magnetic field lines around the observer. In this type of...
We investigate the dynamical effects of cosmic rays (CRs) in isolated disc galaxies. CRs are included as a non-thermal component in the advection-diffusion approximation and are dynamically coupled to the gas in the magneto-hydrodynamical simulations. The CRs are spectrally resolved with a full spectrum ranging from sub-GeV to TeV in every computational cell. We can therefore account for...
Energetic particles may have contributed to the start of life on Earth and exoplanets. The stellar energetic particle and Galactic cosmic ray fluxes that reached Earth at the time when life is thought to have begun is largely determined by the stellar wind properties. The magnetic field strength and velocity profile of a solar-type star’s wind evolve with time. Therefore, the modulation of...
Solar extreme solar proton events (SPEs) form important radiation hazards for modern technological society. The strongest directly observed SPE took place on 23-Feb-1956 as an up to 5000 % increase of the count rate of ground-based neutron monitors. It was characterized by a very hard energy spectrum and strong particle fluence. On the other hand, as known from indirect proxies (cosmogenic...
Since its launch the AlphaMagneticSpectrometer-02 (AMS-02) has delivered outstanding quality measurements of the spectra of cosmic-ray (CR) species, which resulted in a number of breakthroughs, including the spectrum of iron: because of the large fragmentation cross section and large ionization energy losses, most of CR iron at low energies is local, and may harbor some features associated...
The Telescope Array has collected 12 years of data and accumulated the largest to date UHECR data set in the Northern hemisphere. We make use of these data to search for large- and small-scale anisotropy of UHECR. At small angular scales we examine the data for clustering of events and correlations with several classes of putative sources. At intermediate scales we will present a blind search...
Neutron monitors are the main ground-based instruments for continuous measurements the cosmic-ray intensity operating over more than five decades. Those instruments are energy-integrating detectors with count rates governed by the atmospheric and geomagnetic cutoffs. The geomagnetic cutoff dominates (up to 17 GV in rigidity) over most of the globe. However, it is negligible in the polar...
The calculation of asymptotic directions of approach of cosmic ray particles is an important tool in the determination of the rigidity cutoff for a given geographical site. We present the computations results of the asymptotic latitude and longitude and the magnetic rigidity cutoff for the airports located in: Apatity, Oulu, Warsaw, Lae, Buenos Aires Wellington and Mc Murdo at different...
The physical mechanism for the production of fast gamma-ray variability in blazars remains debated. Plasmoids – magnetized quasi-circular structures of plasma formed self-consistently in reconnecting current sheets – are ideal candidates for the production of broadband variable non-thermal emission. Using state-of-the-art kinetic simulations of magnetic reconnection and radiative transfer...
We account for the magnitude, direction and energy dependence of the large-scale anisotropy of ultra-high-energy cosmic rays at energies above 8 EeV and possibly Auger hot spot with the ansatz that the source distribution follows the matter distribution of the Universe. We consider the impact of energy losses during propagation and the deflections by the Galactic magnetic field. We further...
Although supernova remnants remain the main suspects as sources of Galactic cosmic rays up to the knee, the supernova paradigm still has many loose ends. The weakest point in this construction is the possibility that individual supernova remnants can accelerate particles to the rigidity of the knee, ~ 106 GV. This scenario heavily relies upon the possibility to excite current driven...
The origin of UHECR remains one of the most intriguing open question in astroparticle physics. In this work, we delve into this matter by seeking to build a solid understanding of the role of local sources of UHECR, with a few tens of Mpc, in both the energy spectrum and the angular distribution of arrival directions. We present semi-analytical approaches for the propagation of UHECR in...
The sources of ultra-high-energy cosmic rays are still unknown, but assuming standard physics, they are expected to lie within a few hundred megaparsecs from us. Indeed, over cosmological distances cosmic rays lose energy to interactions with background photons, at a rate depending on their mass number and energy and properties of photonuclear interactions and photon backgrounds. The...
The region of the toe in the cosmic-ray spectrum, located at about 45 EeV by the Pierre Auger Collaboration, is of primary interest in the search for the origin of ultra-high energy cosmic rays (UHECRs). The suppression of the flux with increasing energy can be explained by the propagation of UHECRs in intergalactic photon fields, resulting in a shrinking of the observable universe, and/or by...
PG1553+113 is one of the few blazars with a convincing quasi-periodic emission in the gamma-ray band detected by the Fermi-LAT satellite. The source is also a very high-energy (>100 GeV) gamma-ray emitter. The MAGIC collaboration started a multi-year, multi-wavelength monitoring campaign of PG 1553+113 in 2015 involving several instruments in the radio, infra-red, optical photometry and...
Cosmic rays leave their sources mainly along the local magnetic field present in the region around the source and in doing so they excite both resonant and non-resonant modes through streaming instabilities. The excitation of these modes leads to enhanced particle scattering and in turn to a large pressure gradient that causes the formation of expanding bubbles of gas and self-generated...
We present a simulation of magnetosphere transparency for cosmic rays in the last two millennia. Simulations were done in the COR system, in a module for cosmic rays trajectory evaluation in different models of geomagnetic fields for period 0 to 1900 CE. The COR system available at cor.crmodels.org is also briefly presented. The global and local trends for cut-off rigidities evolution in the...
We present MHD+CR simulations probing reacceleration of pre-existing cosmic rays by long-wavelength, subsonic, compressive turbulence. With purely diffusive transport, we recover the scaling relations of Ptuskin 1988, where the reacceleration time reaches a minimum at the ``sweet spot” diffusion coefficient of the sound speed times the outer turbulence scale, $D_{\rm crit} \sim c_{s}L$. For...
The distribution of ultra-high-energy cosmic-ray arrival directions appears to be nearly isotropic except for a dipole moment of order 6 × (E/10 EeV) per cent. Nonetheless, at the highest energies, as the number of possible candidate sources within the propagation horizon and the magnetic deflections both shrink, smaller-scale anisotropies might be expected to emerge. On the other hand, the...
Large-scale anisotropy at the highest energies is essential for the understanding the transition from cosmic rays of galactic origin to those of extra-galactic origin, along with the magnetic fields in the galaxy and those beyond. Motivated by a significant detection of the large-scale anisotropy above 8 EeV by the Pierre Auger Observatory (Auger), we have previously reported, using 11 years...
The total cosmic ray electron spectrum (electrons plus positrons) exhibits a break at a particle
energy of ∼ 1 TeV and extends without any attenuation up to ∼ 20 TeV. Synchrotron and inverse
Compton energy losses strongly constrain both the age and the distance of the potential sources of
TeV and multi-TeV electrons to ≈ $10^5$ yr and ≈ 100 − 500 pc, depending on both the absolute...
The Askaryan Radio Array (ARA) is an ultra-high energy (UHE) neutrino (E_nu > 10^17 eV) detector at South Pole. ARA aims to utilize radio signals detected from UHE neutrino interactions in the glacial ice to infer properties about the interaction vertex as well as the incident neutrino. To retrieve these properties from experiment data, the first step is to extract timing, amplitude and...
Recent studies with IceCube have shown signs of a time-integrated flux of astrophysical neutrinos from point-like sources such as TXS 0506+56 and NGC 1068. Time-variability of this neutrino emission from TXS 0506+56 has been studied extensively by assuming a temporal profile of the possible flare(s) or searching for temporal neutrino correlation with other electromagnetic counterparts....
The Baikal-GVD is a large scale neutrino telescope being constructed in Lake Baikal. The majority of the signals detected by the telescope's photosensors are noise hits, caused primarily by the luminescence in the Baikal water. Separating noise hits from the hits produced by Cherenkov light emitted from the muon track is a challenging part of the muon event reconstruction. We present an...
The objective of the JEM-EUSO program, is the realisation of a space mission devoted to Ultra-High Energy Cosmic Ray (UHECR) science. A super-wide-field telescope will look down from space onto the night sky to detect UV photons emitted from Extensive Air Showers (EAS) generated by UHECRs in the atmosphere. The JEM-EUSO program includes different missions from ground (EUSO-TA), from...
Combining observational data from multiple instruments for multi-messenger astronomy can be challenging due to the complexity of the instrument response functions and likelihood calculation. We introduce a python-based unbinned-likelihood analysis package called i3mla (IceCube Maximum Likelihood Analysis) which is to be used with the public IceCube data format. i3mla is designed to be...
Analysis of anisotropy of the arrival directions of galactic positrons and electrons has been performed with the Alpha Magnetic Spectrometer on the International Space Station. These results differentiate between point-like and diffuse sources of cosmic rays for the explanation of the observed excess of high energy positrons. The AMS results of the dipole anisotropy are presented along with...
The fluxes and flux ratios of charged elementary particles in cosmic rays are presented in the absolute rigidity range from 1 up to 2000 GV. In the absolute rigidity range ∼60 to ∼500 GV, the antiproton, proton, and positron fluxes are found to have nearly identical rigidity dependence and the electron flux exhibits different rigidity dependence. Below 60 GV, the antiproton-to-proton,...
Baikal-GVD is a gigaton-scale neutrino observatory under construction in Lake Baikal. It currently produces about 100GB of data every day. For their automatic processing, the Baikal Analysis and Reconstruction software (BARS) was developed. At the moment, it includes such stages as a hit extraction from PMT waveforms, assembling events from raw data, assigning timestamps to events, determining...
Energetic protons released during solar eruptive events experience scattering during their interplanetary propagation and may cross the spherical surface of radius 1 AU multiple times. Knowledge of N_cross, the average number of 1 AU crossings per particle, is therefore important to deduce the total number of protons in interplanetary space during solar energetic particle events, for example...
The ICARUS T600 detector is the far detector for the Short-Baseline Neutrino (SBN) program at Fermilab, aiming to identify potential neutrino oscillations using the O(1 GeV) neutrino energy Booster Neutrino Beam (BNB). ICARUS is the largest Liquid Argon Time Projection Chamber (LAr-TPC) currently used in neutrino physics, containing 500 tons of Argon in its active volume. LAr-TPC technology...
The field of deep learning has become increasingly important for particle physics experiments, yielding a multitude of advances, predominantly in event classification and reconstruction tasks. Many of these applications have been adopted from other domains. However, data in the field of physics are unique in the context of machine learning, insofar as their generation process and the law and...
We present an analytical model for the fluxes and spectra of positrons accelerated within the intrabinary shocks of compact binary millisecond pulsars (CBMSPs). We find that the minimum energy $E_{\min}$ of the pairs that enter the shock is critical to quantify the energy spectrum with which positrons are injected into the interstellar medium. We measure for the first time the Galactic scale...
The cosmic-ray flux of positrons is measured with high precision by the space-borne particle spectrometers AMS-02. The hypothesis that pulsar wind nebulae (PWNe) can significantly contribute to the excess of the positron ($e^+$) cosmic-ray flux has been consolidated after the observation of a $\gamma$-ray emission at TeV energies of a few degree size around Geminga and Monogem PWNe. In this...
Synchrotron radio emission from non-relativistic jets powered by massive protostars has been reported, indicating the presence of relativistic electrons and mG magnetic fields. We study diffusive shock acceleration and magnetic field amplification in protostellar jets with speeds between 300 and 1000 km/s. We show that the magnetic field in the synchrotron emitter can be amplified by the...
A number of cosmic-ray observatories have measured a change in both phase and amplitude of the dipole component in the distribution of cosmic-ray arrival directions at ~ 100 TeV primary energy. We focus on probing the cosmic-ray dipole and multipole evolution in the energy region of ~ 1 TeV to beyond a PeV with a future large-area gamma-ray observatory, such as the Southern Wide-field...
The AMS-02 experiment has reported precise measurements of energy spectra of several cosmic-ray species in the energy range of ~ (0.5-2000) GeV/n. An intriguing finding is the differences in the spectral shape between the different species. Protons exhibit the steepest spectrum of all the species, and helium, carbon, oxygen and iron spectra are found to be harder than that of neon, magnesium...
Telescope Array (TA) is the largest ultrahigh energy cosmic-ray (UHECR) observatory in the Northern Hemisphere. A surface detector (SD) array covers approximately 700 km$^2$, and the SD array is surrounded by three fluorescence detector (FD) stations. TA has found evidence for a cluster of cosmic rays with energies greater than 57 EeV from the TA SD data. In order to confirm this evidence with...
Several studies have pointed out an excess in the AMS-02 antiproton spectrum at rigidities of 10–20 GV. Its spectral properties were found to be consistent with a dark-matter particle of mass 50–100 GeV which annihilates hadronically at roughly the thermal rate. Here, we reinvestigate the antiproton excess, including all relevant sources of systematic errors. Most importantly, we perform a...
Many upcoming experiments seek to observe high energy cosmic events while observing from either sub-orbital or orbital altitudes, using the Earth atmosphere as an extremely large instrumental volume, thereby increasing the geometric acceptance over ground based instruments in addition to supplying uniform exposure of both hemispheres. In particular, the planned Extreme Universe Space...
The energy spectrum of cosmic rays implies that our Galaxy contains PeV proton accelerators (PeVatrons). However, the origin of PeV cosmic rays is still an open question. Star forming regions (SFR) have long been advised as ideal candidates of PeV cosmic ray accelerators. The gamma-ray radiation of Cygnus Cocoon measured by Fermi-LAT may be produced by newly accelerated cosmic rays from Cygnus...
Despite significant efforts over the last decade, the origin of the cosmic ray positron excess has still not been unambiguously established. A popular class of candidates are pulsars or pulsar wind nebulae but these cannot account for the observed hard spectrum of cosmic ray antiprotons. We revisit the alternative possibility that the observed high-energy positrons are secondaries created by...
IceTop, the surface array of the IceCube Neutrino Observatory, currently consists of 162 ice-Cherenkov tanks distributed over an area of 1km^2. Besides being used as a veto for the in-ice neutrino detector, IceTop is a powerful cosmic-ray detector, and analyses of IceTop data have led to advances in cosmic ray physics. In the upcoming years, the capabilities of the IceTop array will be further...
The discovery of a high-energy cosmic neutrino flux has paved the way for the field of neutrino astronomy. High-energy neutrino sources are yet to be discovered; the KM3NeT detector, which is under construction in the Mediterranean sea, is designed to determine their origin. KM3NeT will instrument a cubic kilometre of seawater with photomultiplier tubes that detect Cherenkov radiation from...
The Galactic cosmic ray (CR) fluxes observed in the vicinity of the Earth encode the space and time averaged properties of their sources and are also shaped by the effects of their propagation in the Galaxy.
A combined study of the spectra of different particle types (protons, primary and secondary nuclei, electrons, positrons and antiprotons) is essential to determine the roles of the source...
The General Antiparticle Spectrometer (GAPS) is the first experiment optimized to identify low-energy (<0.25 GeV/n) cosmic antinuclei, in particular antideuterons from dark matter annihilation or decay. The GAPS program will deliver unprecedented sensitivity to cosmic antideuterons, an essentially background-free signature of various dark matter models, as well as a high-statistics antiproton...
Massive star-forming regions are genuine reservoirs of energy and potential sources of non-thermal particles, but their role in Galactic cosmic-ray acceleration and propagation is still poorly understood. Gamma-ray observations of the Cygnus X star-forming region revealed the presence of a cocoon of freshly-accelerated cosmic rays, making it one of the best examples to investigate these...
The TUS detector was the first space-based mission aimed for ultra-high-energy cosmic ray (UHECR) measurements. The detector was designed to register the fluorescent signal of extensive air showers (EAS) developing in the night atmosphere of Earth in the UV range of 300-400 nm. TUS was launched on board the Lomonosov satellite in April, 2016 and operated till December, 2017. Almost 90...
KM3NeT/ORCA is a water-Cherenkov neutrino detector, currently under construction in the Mediterranean Sea at a depth of 2450 meters. The project's main goal is the determination of the neutrino mass hierarchy by measuring the energy- and zenith-angle-resolved oscillation probabilities of atmospheric neutrinos traversing the Earth. Additionally, the detector will observe a large amount of...
The IceCube Neutrino Observatory is designed to observe neutrinos interacting deep within the South Pole ice. It consists of 5,160 digital optical modules, which are arrayed over a cubic kilometer from 1,450 m to 2,450 m depth. At the lower center of the array is the DeepCore subdetector. It has a denser configuration which lowers the observable energy threshold to the GeV scale and creates...
Galactic charged cosmic rays, notably positrons, antiprotons and light antinuclei, are powerful probes of dark matter annihilation or decay, in particular for candidates heavier than a few MeV or tiny evaporating primordial black holes. Recent measurements by PAMELA, AMS-02, or Voyager on positrons and antiprotons already translate into constraints on several models over a large mass range....
Here we report the new reconstruction of the event-integrated spectra of solar energetic particles (SEP) detected by neutron monitor (NM) network and satellite experiments (mainly GOES data) during ground-level enhancement (GLE) events. The reconstruction of SEP particle fluences is based on the “bow-tie” method employing the latest advances in NM data analysis (time-dependent GCR background...
High precision cosmic-ray antiproton fluxes reported by BESS-Polar, PAMELA and AMS-02 are overall consistent with secondary production from interactions of primary cosmic rays with the interstellar medium. This severely constrains the possibility of antiprotons of primary origin such as annihilation or decay of supersymmetric dark matter or evaporation of primordial black holes. In the case of...
The latest AMS-02 data on cosmic ray electrons show a break in the energy spectrum around 40 GeV, with a change in the slope of about 0.1. We perform a combined fit to the newest AMS-02 positron and electron flux data using a model which includes production of pairs from pulsar wind nebulae (PWNe), electrons from supernova remnants (SNRs) and both species from spallation of hadronic cosmic...
The Cygnus Cocoon is the first gamma-ray superbubble powered by a massive stellar association, the OB2 association. It was postulated that the combined effects of the stellar wind of the massive type O stars of the OB2 association can accelerate the cosmic rays to PeV energy in the Cocoon. The conclusive proof of acceleration to PeV energy in the Cocoon will identify the stellar association as...
We present here the performance of a machine learning-based algorithm to predict the muon multiplicity using a simulated dataset in which the trigger condition was varied. We also show the performance of this algorithm is selecting interesting events in the prototype detector at TIFR.
The Pierre Auger Observatory, located in western Argentina, is the world's largest cosmic ray observatory. While it was originally built to study the cosmic-ray flux above $10^{18.5}$ eV, several enhancements have reduced this energy threshold, thus extending significantly the Observatory's scientific capabilities significantly. One such enhancement, part of the AMIGA original proposal, is a...
Baikal-GVD is a cubic-kilometer scale neutrino detector being
constructed in Lake Baikal. After the deployment campaign in spring
2020 the telescope includes over 2000 optical modules distributed
among 56 strings. Effective volume for the detection of high-energy
charged particle cascades constitutes 0.35 km^3. Muon (anti)neutrino
interactions in the vicinity of the detector through the W...
Primary objectives of the CALET (CALorimetric Electron Telescope) mission are to search for possible nearby cosmic-ray sources and dark matter signatures with the precise measurement of the electron and positron (all-electron) spectrum. The instrument, consisting of a charge detector, an imaging calorimeter and a total absorption calorimeter, is optimized to measure the all-electron spectrum...
Recently, massive star clusters have received renewed attention as possible cosmic-ray (CR) factories. In the neighborhood of a massive star cluster, assuming a steady-state injection lasting a few million years, the density of escaping, freshly accelerated CRs is expected to decrease following a 1/r profile. As CRs diffuse away from the cluster, the hadronic component interacts with molecular...
Star-forming regions have been proposed as potential Galactic cosmic ray accelerators for decades. Cosmic ray acceleration can be probed through observations of gamma-rays produced in inelastic proton-proton collisions, at GeV and TeV energies. We analyze more than 11 years of Fermi-LAT data from the direction of Westerlund 2, one of the most massive and best-studied star-forming regions in...
Signs of anisotropy of the ultra-high-energy cosmic ray (UHECR) arrival direction have been reported by The Telescope Array and The Pierre Auger Observatory. Then, it is expected that source of UHECRs will be clarified. However, because of the quite low flux of UHECR, it is inevitable to extend observatory to much larger than existing ones. Cosmic Ray Fluorescence Fresnel lens Telescope...
Ultra-high energy cosmic rays (UHECRs) are the messengers of the most extreme physics in the cosmos; however, efforts to identify their origins have thus far been thwarted by the fact that they don’t point back to their sources. Using statistical studies cross-correlating UHECR arrival directions with astrophysical catalogs, the ground-based Pierre Auger Observatory has reported hints of a...
Measurements of neutrinos at and below 10 GeV provides unique constraints of neutrino oscillation parameters as well as probes of potential Non-Standard Interactions (NSI). The IceCube Neutrino Observatory’s DeepCore array is designed to detect neutrinos down to GeV scales. This work uses convolutional neural networks (CNNs) to improve the energy reconstruction resolution and speed of...
The IceCube Neutrino Observatory is a cubic-kilometer scale neutrino detector embedded in the Antarctic ice of the South Pole. In the near future, the detector will be augmented by extensions, such as the IceCube Upgrade and the planned Gen2 detector. The sparseness of observed charge in the detector for low-energy events, and the irregular detector geometry, have always been a challenge to...
The Extreme Universe Space Observatory on a Super Pressure Balloon II (EUSO-SPB2) is a second generation stratospheric balloon instrument for the detection of Ultra High Energy Cosmic Rays (UHECRs, E > 1EeV) via the fluorescence technique and of Very High Energy (VHE, E > 10PeV) neutrinos via Cherenkov emission. EUSO-SPB2 is a pathfinder mission for instruments like the proposed Probe Of...
Cosmic rays are mostly composed by protons accelerated to relativistic speeds. When those protons encounter interstellar material, they produce neutral pions which in turn decay into gamma rays. This offers a compelling way to identify the acceleration sites of protons. A characteristic hadronic spectrum was detected in the gamma-ray spectra of four Supernovae Remnants (SNRs), IC 443, W44,...
3D test particle simulations of historic GLE events are performed to investigate the propagation and distribution of solar protons within the heliosphere. Multiple past GLEs are considered that possess a variety of properties of the associated solar events, e.g. a range of source flare longitudes and coronal mass ejection velocities. The test particle model, which includes drift effects, is...
During its 8.5 years of operations on board the International Space Station, AMS has detected several solar energetic particle (SEP) events produced during M- and X-class flares and fast coronal mass ejections. AMS is able to study these SEPs at high energies, below a few GeVs, with unprecedented accuracy. These unique features of the observed SEPs will be presented.
We report here an interesting event that was detected by solar neutron telescopes installed at high altitudes in Bolivia (5250 m a.s.l.) and Mexico (4600 m a.s.l.). The event was observed on November 7th 2004 in association with a large solar flare of magnitude X2.0. Some features of our detectors and in two satellites (GOES 11 and SOHO) reveal the presence of electrons and protons as...
The identification of the sources contributing to the acceleration of Galactic Cosmic Rays (CRs) is a long-standing puzzle. Star-forming regions (SFRs) may be one of these potential contributors, in fact, the detection of gamma rays from the Cygnus Cocoon indicates the existence of freshly accelerated high-energy particles in the region, making it the first case of a firm detection of CR...
The Dortmund Spectrum Estimation Algorithm (DSEA+) is a novel approach to unfolding by translating deconvolution tasks into multinomial classification problems, which enables the use of readily available tools. The algorithm is employable with several prebuilt classification models, making it advantageous to other methods due to its generality, simplicity, and broadness. DSEA+, primarily...
The Auger Muons and Infill for the Ground Array (AMIGA) is an enhancement of the Pierre Auger Observatory that aims to lower its energy threshold down to 10^{16.5} eV and to assess the muonic content of air showers directly. These measurements will significantly contribute to the determination of primary particle masses, to the study of hadronic interaction models with air showers, and, in...
SuperTIGER (Super Trans-Iron Galactic Element Recorder) is a long-duration-balloon instrument that completed its first Antarctic flight during the 2012-2013 austral summer, spending 55 days at an average float altitude of 125,000 feet. SuperTIGER measured the relative abundances of Galactic cosmic-ray (GCR) nuclei with high statistical precision and well resolved individual element peaks from...
The IceCube Neutrino Observatory is a cubic-kilometer-scaled detector located at the Geographic South Pole. The calibration of the directional reconstruction of neutrino-induced muons and the pointing accuracy of the detector has to be verified. For these purposes, the moon is used as a standard candle to not rely exclusively on simulated data: Cosmic rays get absorbed by the moon, which leads...
Observations by the HAWC and HESS telescopes have found extended TeV emission consistent with a handful of young and middle-aged pulsars. In this talk, I will show that these detections have significant implications for our understanding of both pulsar emission and TeV astrophysics. First, the spectrum and intensity of these “TeV Halos” indicates that a large fraction of the pulsar spindown...
23 July 2012, multiple-spacecraft, namely STEREO-A, STEREO-B, and ACE, observed an extremely powerful, superfast interplanetary coronal mass ejection (ICME) together with the ICME-driven shock and associated solar energetic particles (SEPs). We analyze the relationship between the propagation of the shock and the SEP flux with the Parker spiral magnetic field model. Moreover, we simulate the...
Although most massive stars are thought to live inside clusters giving rise to galactic-scale superbubbles, a complete model of cosmic ray production in these objects is still missing in the literature. I present an attempt to model particles acceleration in these systems including all the relevant physical processes. The acceleration mechanisms taking place in superbubbles differ from that...
The Fluorescence Telescope is one of the two telescopes on board the Extreme Universe Space Observatory on a Super Pressure Balloon II (EUSO-SPB2). EUSO-SPB2 is an ultra-long-duration balloon mission that aims at the detection of Ultra High Energy Cosmic Rays (UHECR) (E > 1 EeV) via the fluorescence technique (using a Fluorescence Telescope) and of Very High Energy (VHE) neutrinos (E > 10 PeV)...
Mini-EUSO is a detector observing the Earth in the ultraviolet band from the International Space Station. It was launched in 2019 in the framework of the "Beyond" mission and as part of an agreement between Russian and Italian space agencies.
The main camera has an optical system with two double-sided Fresnel lenses and a focal surface with 2304 channels and a field of view of 44$^o$. The...
Galactic cosmic-rays (GCRs) are thought to be accelerated by the first order Fermi mechanism in strong shocks induced by massive star winds and supernova explosions sweeping across the interstellar medium (ISM). But the phase of the ISM from which the CRs are extracted has remained elusive up to now. Using the latest CR composition data from the AMS-02, Voyager-1 and SuperTIGER experiments, we...
Hypothesis tests based on unbinned log-likelihood (LLH) functions are a common technique used in multi-messenger astronomy, including IceCube's neutrino point-source searches. We present the general Python-based tool "SkyLLH", which provides a modular framework for implementing and executing log-likelihood functions to perform data analyses with multi-messenger astronomy data. Specific SkyLLH...
Routine hybrid observations of the surface detectors (SD) in conjunction with the fluorescence detectors (FD) of the Telescope Array Low-energy Extension (TALE) began in November 2018. In this presentation, we will describe the simulation studies of detector aperture and resolution of the TALE SD, and report on the latest observation results other than the energy spectrum. We are also in the...
IceCube-Gen2, the extension of the IceCube Neutrino Observatory, will feature three main components: a $10\,$km$^3$ optical array in the deep ice, a large-scale radio array in the shallow ice and firn, and a surface detector above the optical array. Thus, IceCube-Gen2 will not only be an excellent detector for PeV neutrinos, but also constitutes a unique setup for the measurement of cosmic-ray...
Since its full commissioning in 2008, the Pierre Auger Observatory has consistently demonstrated its scientific productivity. A major upgrade of the Surface Detector array (SD) improves the capabilities of measuring the different components of extensive air showers. One of the elements of the upgrade consists of new Scintillator Surface Detectors (SSD) placed on top of the Water-Cherenkov...
Massive stellar clusters have recently been hypothesised as candidates for the acceleration of hadronic cosmic rays up to PeV energies. Previously, the H.E.S.S. Collaboration has reported about very extended gamma-ray emission around Westerlund 1, the most massive young stellar cluster in the Milky Way. In this contribution we present an updated analysis that employs a new analysis technique...
Precision results on cosmic-ray electrons are presented in the energy range from 0.5 GeV to 1.4 TeV based on 28.1 million electrons collected by the Alpha Magnetic Spectrometer on the International Space Station. In the entire energy range the electron and positron spectra have distinctly different magnitudes and energy dependences. The electron flux exhibits a significant excess starting from...
The latest precision measurements on the cosmic ray positrons flux by the Alpha Magnetic Spectrometer on the International Space Station are presented. The positron flux exhibits complex energy dependence. Its distinctive properties are (a) a significant excess starting from 25 GeV compared to the lower-energy, power-law trend; (b) a sharp drop-off above 284 GeV; (c) in the entire energy range...
Following the evidence for a hotspot in the arrival directions of the highest energy cosmic rays, the Telescope Array (TA) Experiment undertook the TAx4 upgrade to expand the area of our Surface Detectors (SD) by a factor of 4 and have added new Fluorescence Detector (FD) stations to view over the new SD arrays. Currently, TAx4 consists of 12 FDs and 257 SDs, of a planned 500, at a spacing of...
The nonresonant streaming (Bell) instability plays a crucial role in the confinement and acceleration of cosmic rays (CRs), but the mechanism ultimately responsible for its saturation has never been determined from first principles. We present 1D, 2D, and 3D hybrid (kinetic ions and fluid electrons) plasma simulations in which the saturation of the Bell instability is studied as a function of...
The IceCube Neutrino Observatory instruments about 1 km$^3$ of deep, glacial ice at the geographic South Pole using 5160 photomultipliers to detect Cherenkov light from relativistic, charged particles. Most IceCube science goals rely on precise understanding and modeling of the optical properties of the instrumented ice. A peculiar light propagation effect observed by IceCube is an anisotropic...
Flares of known astronomical sources and new transient phenomena occur on different timescales, from sub-seconds to several days or weeks. The discovery potential of both serendipitous observations and multi-messenger and multi-wavelength follow-up observations could be maximized with a tool which allows for quickly acquiring an overview over both persistent sources as well as transient events...
KM3NeT is a research infrastructure aiming to study astrophysical sources as well as to perform particle physics studies, through the detection of neutrinos in the abyssal depths of the Mediterranean Sea. The KM3NeT/ORCA detector (Oscillation Research with Cosmics in the Abyss), currently under construction, is deployed at 2450m depth near Toulon, France. Its primary goal is to determine the...
The KM3NeT Collaboration is constructing two deep-sea Cherenkov detectors in the Mediterranean Sea, aiming at neutrino oscillation measurements with the ORCA array, while the ARCA array is aimed at neutrino astronomy in the TeV range. In March 2021, a major step will be taken in the construction of ARCA, bringing the total number of detection lines from one to six. If successful, ARCA will...
Astrophysical shocks are believed to efficiently accelerate charged particles, yet electrons need to undergo pre-acceleration to be energetic enough to cross the shock and join the game of acceleration. Understanding the mechanisms responsible for electron pre-acceleration is crucial to solving the shock injection problem. Here, we present PIC simulations of Oblique shocks of varying obliquity...
Addressing the origin of the observed diffuse astrophysical neutrino flux is one of the main challenges in the context of the neutrino astronomy nowadays. Among several astrophysical sources, Gamma-Ray Bursts (GRBs) are considered interesting candidates to be explored. Indeed, being the most powerful explosions observable in the Universe, they are potentially able to achieve the energetics...
Supernova remnants are believed to be the source of galactic cosmic rays, which are then propagating in the Galaxy to generate radio and gamma-ray emission and to finally reach us. Recent particle-in-cell simulations and gamma-ray observations revealed spectacular insight into the particle acceleration process. However, these simulations are subject to fundamental limitations so that it is...
Neutrino emission from Gamma-Ray Bursts (GRBs) has been heavily investigated in the last decades providing a wealth of models which, under different physical conditions, are able to reproduce the observed electromagnetic gamma-ray emission. Among these, the most exploited ones in terms of multi-messenger signals involve neutrinos produced in the optically thin region of the jet, which are...
Baikal-GVD is a cubic-kilometer scale neutrino telescope installed in Lake Baikal. The main goal of this telescope is the neutrino detection via detecting the Cherenkov radiation of the secondary charged particles originating in the interactions of neutrinos. The basic detection unit of this telescope is a photo-multiplier tube enclosed in a pressure resistant glass sphere – optical module....
Radio and X-ray observations of radio relics indicate acceleration of relativistic electrons at merger shocks in galaxy clusters. These large-scale shocks can also be sites of ultra-high-energy cosmic ray production. It is assumed that diffusive shock acceleration (DSA) produces synchrotron-radiating electrons but the process of electron pre-acceleration from thermal to supra-thermal energies...
Motivated by simulations of non-relativistic high Mach number shocks in supernova remnants, we investigate the evolution of relativistic electron beams in the extended foreshock of oblique shocks. The instabilities mainly responsible for heating and scattering of shock-reflected electrons are identified in two-dimensional particle-in-cell simulations of the foreshock region.
In their early...
The origin of cosmic rays is still a long-standing problem in astrophysics. Supernova remnants are plausible candidates of cosmic rays up to 10^15.5 eV. For cosmic ray nuclei, the maximum energy is limited by the escape from accelerators. In previous studies about the cosmic-ray escape, the diffusion approximation is assumed. However, the diffusion approximation cannot apply to investigate the...
The multi-messenger era is now well underway, with high-energy neutrinos providing a unique opportunity to study particle acceleration. Recent reports describe possible coincident detections of single IceCube neutrinos with both a flaring blazar and a tidal disruption event. While compelling, these sources cannot be considered in isolation. I will present various strategies to put these...
Millisecond pulsars are very likely the main source of gamma ray emission from globular clusters. However, the relative contributions of two separate emission processes-curvature radiation from millisecond pulsar magnetospheres vs. inverse Compton emission from relativistic pairs launched into the globular cluster environment by millisecond pulsars-has long been unclear. In this talk, I will...
Microquasars, the local siblings of extragalactic quasars, are binary systems comprising a compact object and a companion star. By accreting matter from their companions, microquasars launch powerful winds and jets, influencing the interstellar environment around them. Steady gamma-ray emission is expected to rise from their central objects, or from interactions between their outflows and the...
Challenges faced by researchers in multi-messenger astroparticle physics include: computing-intensive search and preprocessing related to the diversity of content and formats of the data from different observatories as well as to data fragmentation over separate storage locations; inconsistencies in user interfaces for data retrieval; lack of the united infrastructure solutions suitable for...
The extended jets of the microquasar SS 433 have been observed in radio, optical, X-ray, and recently very-high-energy gamma-ray by HAWC. The multi-wavelength detections motivate searches for high-energy gamma-ray counterparts in the Fermi-LAT data in the 100 MeV– 300 GeV band. We report on the first-ever joint analysis of Fermi-LAT and HAWC observations to study the spectrum and location of...
Using fully-kinetic plasma simulations, we study the non-resonant (Bell) streaming instability driven by energetic leptons. We identify the necessary conditions to drive the Bell instability and the differences from the standard proton-driven case in both linear and saturated stages. A simple analytic theory is presented to explain simulations. Our findings are crucial for understanding the...
We report the detection of pulsed emission from the Geminga pulsar (PSR J0633+1746) with the MAGIC Telescopes. After the Crab and Vela pulsars, Geminga is the third one detected in the very high energy domain, and its estimated age of ~340 ky makes it the oldest one. The spectrum derived by MAGIC extends from ~15 GeV to 75 GeV and can be well modeled with a simple, soft power-law function. For...
There are a number of binary systems in our Galaxy, typically consisting of a compact object and a non-degenerate companion star, that produce X-ray and gamma-ray emission. Depending on the energy at which their emission peaks, they are called either X-ray or gamma-ray binaries. Two main scenarios have been proposed to explain the observed radiation, one involving matter accretion and jet...
Collisionless shocks are present everywhere in the universe, from the solar environment to distant supernovae. They are often associated with strong magnetic fields due to strong nonthermal radiation. However, it is still not well understood how magnetic fields are amplified at scales of the shock thickness. Here we use a set of large-scale Particle-In-Cell (PIC) simulations of...
The Baikal-GVD detector (Gigaton Volume Detector) is a large-scale neutrino telescope located at a depth of 1366 metres in Lake Baikal. One of its main purposes is to identify high-energy extraterrestrial neutrinos and to locate their sources on the sky. In recent (year 2020), it is a three dimensional array of 2016 optical modules (OMs), sub-arranged into 7 functionally independent units...
The Astrophysical Multimessenger Observatory Network (AMON) receives subthreshold data from multiple observatories in order to look for coincidences. Combining more than two datasets at the same time is challenging because of the range of possible signals (time windows, energies, number of events…). However, outlier detection methods can circumvent this issue by identifying any signal...
Ground-based Air-Cherenkov telescopes have detected pulsations at energies above 50 GeV from a growing number of Fermi pulsars. These include the Crab, Vela, PSR B1706-44 and Geminga, with the first two having pulsed detections above 1 TeV. There appears to be VHE emission that is an extension of the Fermi spectra to high energies as well as additional higher-energy components that require a...
Globular clusters are multi-band emitters, with their gamma-ray emission having been variously attributed as due to dark matter annihilation, a resident gamma-ray burst, white-dwarf population, or a millisecond-pulsar population hosted by the cluster. Terzan 5 has plausibly been detected in the gamma-ray band by H.E.S.S., which produced constraining stacking upper limits on the integral...
The Baikal-GVD deep underwater neutrino experiment participates in the international multi-messenger program on discovering the astrophysical sources of high energy fluxes of cosmic particles, while being at the stage of deployment with a gradual increase of its effective volume to the scale of a cubic kilometer. The effective volume of the detector has been reached 0.35 km3 for cascade...
The Pacific Ocean Neutrino Experiment (P-ONE) collaboration, currently forming around Ocean Networks Canada (ONC), including Canadian as well as German universities, pursues the goal of constructing a new large-scale neutrino telescope at the 2600 m deep Cascadia Basin, off the Canadian coast. While the instrumented volume needs to be at least on the order of km³ for the physics goals of P-ONE...
Diffusive shock acceleration (DSA) in supernova remnants is widely accepted as a plausible mechanism to produce galactic cosmic rays. However, several problems are pointed out to this picture and some modifications are needed to understand cosmic ray acceleration in SNRs. In our previous work (Yokoyama & Ohira, 2020), we considered a shock wave propagating to an inhomogeneous medium, although...
Although supernovae remnants can accelerate cosmic rays up to PeV energies, the origin of more energetic particles remains uncertain. In particular, standard diffusive shock acceleration in isolated shocks does not explain some features in the spectrum such as the so-called "knee" and "ankle". Other acceleration mechanisms should therefore be considered. I describe the time-dependent...
Context. Supernova Remnants (SNRs) are considered as the primary sources of galactic cosmic rays (CRs), where CRs are assumed to be accelerated by diffusive shock acceleration (DSA) mechanism, specifically at SNR shocks. The SNR shocks expand in the complex ambient environment, particularly in the core-collapse scenarios as the core-collapse SNRs evolve inside wind-blown bubbles created...
Relativistic shocks are ubiquitous in the universe, in which synchrotron maser instability produces intense electromagnetic precursor waves. Recent one-dimensional Particle-in-Cell (PIC) simulations show that longitudinal electrostatic waves, which are called wakefields, are induced in the wake of the large-amplitude electromagnetic waves and that nonthermal particles are generated during the...
Electron and ion acceleration at a non-relativistic collisionless shock is studied by employing large scale one-dimensional particle-in-cell (PIC) simulations in the de-Hoffmann and Teller (dHT) frame of reference. We demonstrate that diffusive shock acceleration of both electrons and ions occurs in quasi-perpendicular shocks configurations at large Alfven Mach numbers. We also identify the...
Origin of cosmic rays (CRs) is still not known. In this work we argue that PeV cosmic rays can be accelerated during the early phase of a supernova blast wave expansion in dense red supergiant winds. We solve in spherical geometry a system combining a diffusive-convection equation which treats CR dynamics coupled to magnetohydrodynamics to follow gas dynamics. The fast shock expanding in a...
POLAR is a dedicated Gamma-Ray Burst polarimeter making use of Compton-scattering which took data from the second Chinese spacelab, the Tiangong-2 from September 2016 to April 2017. It has a wide Field of View of $\sim6$ steradians and an effective area of $\sim400\ cm^2$ at 300 keV. These features make it one of the most sensitive instruments in its energy range (15-500 keV), and therefore...
Astrophysical tau neutrinos can cause double pulse waveform signals in IceCube photon sensors. A previous 8-year analysis has found three tau neutrino candidates and the most promising one which is located very near to the dust layer in the detector. We will present a posteriori analysis on this event using a new ice model treatment with continuously varying parameters to do targeted volume...
Black widow and redback systems are compact binaries in which a rotation-powered millisecond pulsar interacts with its low-mass companion. In such systems, an intrabinary shock can form as a site of particle acceleration and associated nonthermal emission. We model the X-ray and gamma-ray synchrotron and inverse Compton spectral components for select spider binaries, including diffusion,...
The detail of the particle acceleration at trans-relativistic shocks is still under debate. We propose a way to probe the particle acceleration at trans-relativistic shocks with observations of gamma-ray burst (GRB) afterglows. In the afterglow phase, the shock wave launched in a GRB is gradually decelerated from the relativistic to non-relativistic regimes by sweeping up the ambient...
KM3NeT is a multi-purpose cubic-kilometer neutrino observatory in construction in the Mediterranean Sea. It consists of ORCA and ARCA (for Oscillation and Astroparticle Research with Cosmics in the Abyss, respectively), currently both with a few detection lines in operation. Although having different primary goals, both detectors can be used for neutrino astronomy over a wide energy range,...
Realtime analyses are necessary to identify the source of high energy neutrinos. As an observatory with a 4π steradian field of view and near-100% duty cycle, the IceCube Neutrino Observatory is a unique facility for investigating transients. In 2016, IceCube established a pipeline that uses low-latency data to rapidly respond to astrophysical events that were of interest to the...
Cosmic-rays interacting with nucleons in the solar atmosphere produce a cascade of particles that give rise to a flux of high-energy neutrinos and gamma-rays. Fermi has observed this gamma-ray flux; however, the associated neutrino flux has escaped observation. In this contribution, we put forward two strategies to detect these neutrinos, which, if seen, would push forward our understanding of...
IceCube is a cubic-kilometer scale neutrino detector instrumenting a gigaton of ice at the geographic South Pole in Antarctica. On average, 8 track-like high-energy neutrino events with a high probability of being of astrophysical origin are detected per year. These events produce an extended signal in the detector that allows the events to be reconstructed with good angular precision, making...
The open air, wide-angle integrating Cerenkov array TAIGA-HiSCORE (FOV ~0.6 ster) is part of the TAIGA installation for high-energy gamma-ray astronomy and cosmic ray physics. Today this array includes nearly 100 optical detector stations distributed over an area of ~1 km$^2$ in Tunka Valley near lake Baikal, Siberia, Russia. Due to high accuracy and stability of time synchronization of the...
Astrophysical sources capable of hadronic acceleration to relativistic energies have long been believed to be sources of high-energy astrophysical neutrinos. The lack of significant indication of point sources in the long-exposure neutrino sky map may point to a large population of faint, steady sources or flaring objects as the origin of the diffuse flux. The spatially and temporaly...
The interaction of cosmic-rays with the solar atmosphere can yield neutrinos as final state
particles. These neutrinos are expected to be mainly produced at the surface of the Sun and to be
absorbed in the inner part.
Solar Atmospheric Neutrinos represent an irreducible source of background to solar dark
matter searches, and its detection would be important in the characterization of...
The peculiar radio-quiet PSR J2021+4026, in the Gamma Cygni supernova remnant, is one of the brightest of the >250 pulsars detected by Fermi-LAT. It is unique in being the only known isolated gamma-ray pulsar to undergo abrupt flux changes simultaneous with spin-down variations. The first change was observed by Fermi-LAT in October 2011, and it was followed by a recovery over a timescale...
1A 0535+262 is a Be X-ray binary pulsar and one of the only galactic pulsar systems to show radio jet emission. Characterizing the very high energy emission (VHE, >100 GeV) in these extreme microquasars is critical to understanding their contribution to the origin of galactic cosmic rays. The 2020 giant outburst of this system, where X-ray fluxes exceeded 12 Crab, marked a rare opportunity to...
In the multi-messenger era, space and ground-based observatories usually develop real-time analysis (RTA) pipelines to rapidly detect transient events and share information with the scientific community as quickly as possible, allowing follow-up observations. These RTA pipelines can also react to science alerts shared by other observatories through networks such as the Gamma-Ray Coordinates...
The next generation neutrino telescope Baikal-GVD is placed in open water of Lake Baikal. The aim of the experiment is the detection of high energy astrophysical neutrinos. In particular, the goal is the registration of the Cherenkov radiation emitted when charged particles are passing through the deep water in Lake Baikal. The detector is indeed a three-dimensional array of photo-sensors ...
Baikal-GVD is a next generation, kilometer-scale neutrino telescope currently under construction in Lake Baikal. GVD is formed by multi-megaton subarrays (clusters) and is designed for the detection of astrophysical neutrino fluxes at energies from a few TeV up to 100 PeV. The design of Baikal-GVD allows one to search for astrophysical neutrinos with flux values measured by IceCube already at...
The Cherenkov Telescope Array (CTA), with tens of telescopes located in both the northern and southern hemispheres, will be the largest ground-based gamma-ray observatory with an energy coverage from 20 GeV to 300 TeV. The large effective area and field-of-view, coupled with the fast slewing capability and unprecedented sensitivity, make CTA a crucial instrument for the future of ground-based...
The recent discoveries in the theory of diffusive shock acceleration (DSA) that originate from first-principle kinetic plasma simulations are discussed. We show that, when ion acceleration is efficient, the back-reaction of non-thermal particles and self-generated magnetic fields becomes prominent and leads to both enhanced shock compression and particle spectra significantly softer than the...
The observation of a neutrino (IC 191001A) in association with the Tidal Disruption Event (TDE) AT2019dsg has revealed a new source class producing astrophysical neutrinos. We discuss the theoretical modeling of this multi-messenger observation in a jetted concordance scenario, highlighting the connection with X-ray observations. We illustrate how the late-term neutrino observation about 150...
Cosmic-ray acceleration at non-relativistic shocks relies on scattering by turbulence that the cosmic rays drive upstream of the shock. We explore the rate of energy transfer from cosmic rays to non-resonant Bell modes and the spectral softening it implies. Accounting for the finite time available for turbulence driving yields a much smaller spectral impact than found earlier with steady-state...
I shall review our recent proposal of the use of the harmonic-space cross-correlation power spectrum between the arrival directions of ultra-high energy cosmic rays (UHECRs) and the distributions of galaxies in the Universe, as observed by cosmological surveys of the large-scale structure (LSS). We expect the two observables to correlate, due to both galaxies and UHECR sources being hosted...
Time variability of the X-ray flux of supernova remnants enables us to probe the evolution of the local magnetic field and the particle acceleration at interstellar shocks. High spatial resolution multiepoch (from 2000 to 2014) Chandra observations of Cassiopeia A supernova remnant have shown evidence of variation up to 50% of the 4.2-6 keV flux in six distinct regions located on the west side...
Recent detection of the Vela pulsar in the GeV band up to $\sim$100 GeV by both H.E.S.S. and the Fermi Large Area Telescope provides evidence for a curved spectral component in this band, distinct from the TeV pulsed emission seen by H.E.S.S. up to $\sim$7 TeV. We interpret these GeV pulsations to be the result of curvature radiation due to primary particles in the pulsar magnetosphere,...
When charged particles cross an astrophysical shock, they can be accelerated through diffusive shock acceleration (DSA) aka Fermi-1 acceleration. This process involves repeated shock crossings, which occur if the particles are reflected toward the shock by the magnetic field. If the particles reach relativistic speeds, they become known as cosmic rays (CRs).
This process is difficult to...
LS I +61 303 is one of around ten gamma-ray binaries detected so far, each characterized by a spectral energy distribution dominated by MeV-GeV photons. It is located at a distance of 2 kpc and consists of a compact object (black hole or neutron star) in an eccentric orbit around a 10-15 𝑀⨀ Be star, with an orbital period of 26.5 days. The binary orbit modulates the emission ranging from radio...
The EAS detector system consisting of timing detection is being built for the reconstruction of the EAS axis direction using chronotron timing information. This system consists of eight scintillator-based individual detectors (100 x 100 x 1 cm) using wavelength shifting fibers for light collection. The goal of the project is to supplement the Horizon-T detector system that is located at the...
Despite the enormous efforts done in very recent years, both theoretically and experimentally, the basic three questions about the CR origin remain without clear answers: what are their sources, how are they accelerated, how do they propagate?
Gamma-ray astronomy plays a fundamental role in this field. Both relativistic protons and electrons can emit in the gamma-ray band with different...
K-EUSO is a planned mission of the JEM-EUSO program for the study of Ultra High Energy Cosmic Rays (UHECR) from space. The K-EUSO observatory consists of a UV telescope, to be deployed on the International Space Station, with a wide field of view, that aims at the detection of the fluorescence light emitted by Extensive Air Showers (EAS) in the atmosphere. The EAS events will be sampled with a...
The IceCube Neutrino Observatory first observed a diffuse flux of high energy astrophysical neutrinos in 2013. Since then, this observation has been confirmed in multiple detection channels such as high energy starting events, cascades, and through-going muon tracks. Combining these event selections into a global fit of IceCube's neutrino data could strongly improve the understanding of the...
The principle of Air Shower Universality yields a method of understanding Extensive Air Showers of UHECRs as a superposition of different particle components whose spatial and temporal distributions follow individual analytical profile functions. We present a model of the expected densities of particles in time and space that uses the depth of the shower maximum,
$X_\text{max}$, and the...
Cosmic Rays (CR) are a powerful tool for the investigation of the structure of the magnetic fields in the galactic halo and the property of the Inter-Stellar Medium.
Two parameters of the Cosmic Ray propagation models: the galactic halo thickness, H, and the diffusion coefficient, D, are loosely constrained by current CR flux measurements, in particular a large degeneracy exists being only...
After 10 years of operations of the Large Area Telescope (LAT), a high-energy pair-creation telescope onboard the Fermi satellite, the Fermi Collaboration has produced two major catalogs: the 4FGL and the 3FHL. These catalogs represent the best sample of potential very high energy (VHE) emitters that may be studied by Imaging Atmospheric Cherenkov Telescopes (IACTs). Several methods are used...
Recent observations by the Alpha Magnetic Spectrometer (AMS-02) have tentatively detected a handful of cosmic-ray antihelium events. Such events have long been considered as smoking-gun evidence for new physics, because astrophysical antihelium production is expected to be negligible. However, the dark-matter-induced antihelium flux is also expected to fall below current sensitivities,...
The main detector to provide data to study highly energetic (above ~400 MeV) solar particles is the network of ground-based neutron monitors (NMs). Solar events recorded on the ground are called ground-level enhancements (GLEs). All GLE-related data from the NM network are collected in the International GLE Database (IGLED, https://gle.oulu.fi ), which provides formal NM count-rate increases...
The emission of very-high-energy photons (VHE, E>100 GeV) in active galactic nuclei (AGN) is closely connected with the production of ultra-relativistic particles. Among AGN, the subclass of extreme BL Lacertae are of particular interest because they challenge state-of-art models on how these cosmic particle accelerators operate. By cross-matching two gamma-ray catalogs (this is, 4FGL-DR2 and...
Blazars are among the most powerful steady sources in the Universe. Multi-messenger searches for blazars have traditionally focused on their gamma-ray emission, which can be produced simultaneously with neutrinos in photohadronic interactions. However, X-ray data can be equally vital to constrain the SED of these sources, since the hadronically co-produced gamma-rays could get absorbed by the...
We present a new efficient calculation to propagate cosmic ray muons from the surface of the Earth to deep underground laboratories, allowing us to look at the physics and performance of various models of high-energy cosmic rays. The evolution of cosmic rays in the Earth's atmosphere is computed with MCEq (Matrix Cascade Equation), taking into account different combinations of primary and...
We propose a monitor that attempts to measure the Cosmic X-ray Background (CXB) in the 10-100 keV energy band with unprecedented precision, so as to: 1). help to understand the source population of CXB, most of which are proposed to be Active Galactic Nuclei (AGNs); 2). study the anisotropy of CXB intensity over the sky, which helps to understand the large-scale structure of the Universe. An...
The Tibet ASγ experiment located at 4300 m above sea level, Tibet, China, has a wide field of view and large effective area. It consists of the Tibet air-shower array (Tibet-AS), the air-shower core-detector array (YAC) and the underground water-Cherenkov muon-detector array (Tibet-MD). The Tibet-MD array significantly improves gamma-ray sensitivity in the 10-1000 TeV energy region by an order...
Starburst galaxies (SBGs) and more in general starforming galaxies represent a class of galaxies with a high star formation rate (up to 100 Mo/year). Despite their low luminosity, they can be considered as guaranteed “factories” of high energy neutrinos, being “reservoirs” of accelerated cosmic rays and hosting a high density target gas in the central region. The estimation of their point-like...
Hadronic interactions of highly energetic projectiles in matter induce rich cascades of daughter particles, an example being atmospheric neutrinos produced in cosmic ray air showers. Fully analytical modelling of such cascades, due to the amount and the complexity of the coupled processes involved, is infeasible, while Monte Carlo simulations remain computationally expensive. These...
We explore analytical techniques for modeling the nonlinear cosmic ray transport in various astrophysical environments which is of significant current research interest. While nonlinearity is most often described by coupled equations for the dynamics of the
thermal plasma and the cosmic ray transport or for the transport of the plasma waves and the cosmic rays, we
study the case of a...
The Latin American Giant Observatory (LAGO) is an international experiment spanning over 10 Latin American countries and Spain. LAGO scientific objectives include the study of gamma-ray bursts and space weather phenomena using water Cherenkov detectors (WCDs) deployed at different latitudes and altitudes. Large area (8-9 inches) photomultiplier tubes (PMTs) sense the Cherenkov radiation...
Very inclined extensive air showers, with both down-going and up-going trajectories, are particularly targeted by the next generation of extended radio arrays, such as GRAND. However, the reconstruction of their incoming direction, core position, primary energy and composition, remains underdeveloped.
Towards that goal, we present a new reconstruction procedure based on the arrival times...
Large High-Altitude Air Shower Observatory (LHAASO) has one square kilometer array of scintillator detectors and muon detectors, 18 Imaging Atmospheric Cherenkov telescopes and a 78,000 square meter Water Cherenkov Detector Array. LHAASO located at very high altitude (around 4410 m a.s.l.) in China. Multi-parameter observation of showers allows to measurement the energy spectrum, elemental...
In this paper we introduce an original scientific and educational experience conducted with Italian 16/17 years-old students attending Scientific Lyceum "Mangino" of Pagani (Italy). It was inserted in an Italian Educational Program PCTO (i.e. Percorsi per le Competenze Trasversali e per l'Orientamento), active in High Schools on a national level, with the aim to make students consolidate and...
When the lifetime of dark matter is much longer than the age of the Universe, the current abundance of dark matter can be explained with non-thermal, superheavy dark matter models. In these scenarios, dark matter decays can produce highly energetic neutrinos, along with other Standard Model particles. To date, the IceCube Neutrino Observatory is the world’s largest neutrino telescope, located...
The High Altitude Water Cherenkov (HAWC) Observatory is a wide-field-of-view gamma-ray observatory that is optimized to detect gamma rays between ~300 GeV and several hundred TeV. The HAWC Collaboration recently released their third source catalog (3HWC), which contains 65 sources. One of these sources, the ultra-high-energy gamma-ray source 3HWC J1908+063, may exhibit a hardening of the...
The Pierre Auger Observatory is the most sensitive detector to primary photons with energies
above ∼ 0.2 EeV. It measures extensive air-showers using a hybrid technique that combines
a fluorescence detector (FD) with a ground array of particle detectors (SD). The signatures
of a photon-induced air-shower are a larger atmospheric depth at the shower maximum
(Xmax) and a steeper lateral...
Icecube neutrino detector traces energetic TeVs-PeVs neutrino signals by their cascades or by their tracks inside its kilometer icy cube volume. Cascades are mostly for electron or tau or neutral current, tracks for muons. Cascades show mostly poor directionality. Tracks are sharp in directionality. TeVs-PeVs muon tracks are either born inside, HESE, or outside Icecube. These more abundant...
Aiming at exploring the southern gamma-ray sky in the highest energy range, we are proceeding with the ALPACA project. Also, as the prototype experiment of ALPACA, the ALPAQUITA experiment is in preparation, and its detector is now under construction. ALPAQUITA consists of a surface air shower array and an underground water Cherenkov muon detector. To get the most out of ALPAQUITA, we work on...
This contribution aims to introduce the single photoelectron system designed to calibrate the camera of the Medium-Sized Telescopes of the Cherenkov Telescope Array (CTA). This system will allow us to measure accurately the gain of the camera's photodetection chain and to constrain the systematic uncertainties on the energy reconstruction of gamma rays detected by CTA. The system consists of a...
Cosmic Rays are the most likely source of non-thermal emission in galaxy clusters. These emissions are found at merger shocks where they can be observed as highly polarized radio relics, in jets of AGNs and sometimes as a diffuse radio halo across the entire galaxy cluster. Self-consistent simulations of these observations have been a challenge over the last decades, as they require models for...
The autocorrelation analysis using the arrival direction of Ultra High Energy Cosmic Rays (UHECRs) has been previously reported by the Telescope Array (TA) experiment. It is expected that the autocorrelation function reflects the source distribution. We simulate the expected arrival direction distribution of the cosmic rays using the catalogs of candidate sources. We take into account random...
The low energy cosmic-ray (CR) fluxes measured by space-borne instruments are
generally considered to consist of the gradually changing galactic cosmic rays
(GCRs) and the short-lived solar energetic particles (SEPs). The SEP events cause the sharp and ephemeral increases in the time profile of CR observations with higher occurrence rate in solar maximum. It is necessary to eliminate such...
Clusters of galaxies — with their turbulent magnetic fields and abundant matter content — are a promising class of potential neutrino sources. Cosmic rays accelerated within the large-scale shocks, Active Galactic Nuclei (AGN), or both can be confined in galaxy clusters over cosmological timescales and produce a steady flux of neutrinos in secondary interactions. The IceCube Neutrino...
The flux of cosmic rays in the heliosphere is subjected to variations that are related to the Sun's magnetic activity. To study this effect, updated time series of multichannel observations are needed. Here we present a web application that collects real-time data on solar activity proxies, interplanetary plasma parameters, and charged cosmic-ray data. The data are automatically retrieved on...
The origin and acceleration mechanism of ultra-high-energy cosmic rays (UHECR) with energy exceeding the GZK-cutoff limit remain unknown. It is often speculated that supermassive black holes (SMBHs) located at the centers of many galaxies can serve as possible sources of UHECR. This is also supported by recent observations of high-energy neutrinos from blazar, as neutrinos are the tracers of...
The Cherenkov Telescope Array (CTA) is the next generation ground-based imaging atmospheric Cherenkov telescope (IACT) observatory. Building on the strengths of current IACTs, CTA is designed to achieve an order of magnitude increase in sensitivity, with unprecedented angular and energy resolution. CTA will also increase the energy reach of ground-based gamma-ray astronomy, observing photons...
Feedback processes by active galactic nuclei in the centres of galaxy clusters appear to prevent large-scale cooling flows and impede star formation. However, the detailed heating mechanisms remain uncertain. Promising heating scenarios invoke the dissipation of Alfvén waves that are generated by streaming cosmic rays (CRs) or the dissipation of cluster turbulence. In order to study the idea...
The ANTARES neutrino telescope, located in the Mediterranean Sea, is the longest-operated under-sea neutrino detector, having collected data for more than 14 years and since 2008 in its full configuration. These data have been used to search for a diffuse flux of cosmic neutrinos, upgrading previously published results both in terms of livetime and in search method. In particular, a new event...
Over two decades, I have been actively involved in teaching astronomy and astrophysics to Chicago Public School (CPS) students and their teachers. This work was mainly in collaboration with Don York and the CUIP group. Don is now retired, but I am carrying on doing E/PO. Valuable resources that we have created for schools include the Multiwavelength Astronomy Website, with modules for...
Recent multi-wavelength observations indicate that some starburst galaxies show a dominant nonthermal contribution from its central region. These active galactic nuclei (AGN)-starburst composites are of special interest, as both phenomena on their own are potential sources of high-energetic cosmic rays. In this presentation we will focus on NGC 1068, which is known since several years from its...
The survival probabilities of muon after penetrating through matters are evaluated analytically by solving the diffusion equation, taking account of positron-electron pair production, bremsstrahlung and photonuclear interactions, together with ionization loss. Accuracies of the results are discussed by comparing them with those derived by a Monte Carlo method. Qualitative properties of the...
Atmospheric neutrinos, produced by cosmic ray interactions, are a unique probe to study neutrino oscillations and exotic phenomena beyond the standard model, as well as the main background to measurements of astrophysical neutrinos. Due to the higher precision of next generation detectors, flux uncertainties are increasingly impacting such studies, in particular driven by the lack of...
The next Galactic supernova presents a once-in-a lifetime opportunity to obtain detailed information about the explosion of a star and the extreme conditions found within its core. A core-collapse supernova will produce a neutrino burst visible up to half a day before electromagnetic radiation from the explosion, so the burst will provide an early warning for optical follow-up. Since local...
The GRAPES-3 extensive air shower (EAS) array located at Ooty is equipped with 400 plastic scintillator detectors spread over an area of 25000 m$^2$ and a muon telescope of area 560 m$^2$ built with 3,712 proportional counters. One of its principal objectives is to measure the primary cosmic ray energy spectrum in the TeV-PeV energy region. The response of the photo-multiplier tubes (PMTs)...
Low energy anti-deuterons in cosmic rays are considered a golden channel for the search of Dark matter annihilations in the galaxy.
Anti Deuteron Helium Detector (ADHD) project is aiming to study the signatures offered by an high pressure Helium target for the identification of anti-deuterons in cosmic rays.
In particular exotic atoms are produced by stopping anti-protons/anti-deuterons in...
With a mass of approximately ~10^12 solar masses, the Galactic Halo is the closest known large dark matter halo and a prime candidate for indirect dark matter detection. The High Altitude Water Cherenkov Observatory (HAWC) is a high energy (300 GeV to 100 TeV) gamma ray detector located in central Mexico. HAWC operates via the water Cherenkov technique and has both a wide field of view of ~2...
One of the main objectives of the CREDO project is to search for so-called Cosmic-Ray Ensembles (CRE). To confirm the existence of such phenomena a massive scale observation of even relatively low energy Extensive Air Showers (EAS) and an analysis of their correlations in time must be performed. To make such observations possible, an infrastructure of widely spread detectors connected in a...
The Telescope Array is the largest ultra-high energy cosmic ray hybrid detector in the Northern hemisphere. While the TAx4 Surface Detector (TAx4 SD) has a duty cycle of ~ 100%, it should be noted that the TAx4 Fluorescence Detector (TAx4 FD) observes the full longitudinal profile of the cosmic ray air showers and therefore is able to determine their energies more accurately than TAx4 SD. In...
Jets are ubiquitously in association with different celestial objects. However, most of previous theoretical studies of them rely on numerical calculations, not being able to provide a more convenient way for understanding rather abundant observational results. Now we have obtained a general analytical solution for describing a magnetically dominated jet, through separating the jet “core...
As cosmic rays (CRs) propagate in the Galaxy, they can be affected by magnetic structures that temporarily trap them and cause their trajectories to display chaotic behavior, therefore modifying the simple diffusion scenario. When CRs arrive at the Earth, they do so anisotropically. These chaotic effects can be a fundamental contributor to this anisotropy. Accordingly, this requires a...
ANTARES and Baikal-GVD are both Cherenkov neutrino telescopes located in
the Northern Hemisphere. As a consequence, their fields of view overlap al-
lowing for a combined study of the sky. ANTARES sends alerts after a fast on-
line analysis based on energy and reconstruction direction of track-like events.
From December of 2018 up to the beginning of 2021, Baikal-GVD received 38
ANTARES...
In 2017, a high-energy muon neutrino detected by IceCube was found positionally coincident with the direction of a known blazar, TXS 0506+056, in a state of enhanced $\gamma$-ray emission. Soon after, IceCube reported a compelling evidence for an earlier neutrino flare from the same direction found in the archival data, this time not accompanied by any observed electromagnetic activity.
The...
The studies of antinuclei cosmic rays (CR) are currently of great interest as they represent one of the most promising indirect probes of annihilations or decays of dark matter (DM) candidates and few experiments are looking for traces of antideuterons and antihelium near Earth. However, the antinuclei CR also contain a background contribution from antinuclei produced in CR collisions with...
We have developed the desensitized nuclear emulsion films suitable for the detection of heavy cosmic ray nuclei in the high speed image processing systems (HTS) which was utilized at Nagoya University. And we have carried out our balloon flight of nuclear emulsion telescope for high resolution gamma-ray imaging of Vela Pulsar in April, 2018. We have deployed the emulsion chamber which...
Systematic studies of solar energetic particles (SEPs) provide a basis to understand their acceleration and propagation in the interplanetary space. During solar eruptive processes, such as solar flares and/or coronal mass ejections solar ions can be accelerated to high energy. In the majority of cases, the maximum energy of the accelerated solar ions is several tens of MeV/nucleon, but...
The upgraded surface detectors of the Pierre Auger Observatory will provide data that enables the separation of signals due to the muonic component of extensive air showers. Such information permits the application of new event reconstruction methods, that will contribute to composition studies of high-energy cosmic rays and the understanding of their origin. Considering the idea of using the...
The technique of monitoring the moisture content in soil using CR neutron detectors of special design is being actively developed. For mountainous areas and northern countries, monitoring of the thickness of the snow cover is also relevant. The technology makes it possible to bridge the gap between local measurements and remote sensing on a catchment scale (100×100 km2) using spacecraft. It...
Cosmic-ray accelerators capable of reaching ultra-high energies are expected to also produce very-high energy neutrinos via hadronic interactions within the source or its surrounding environment. Many of the candidate astrophysical source classes are either transient in nature or exhibit flaring activity. Leveraging the Earth as a neutrino converter, suborbital and space-based optical...
We report three AstroSat observations of BL Lacertae object OJ 287. The three observations caught it in very different flux states that are connected to different broadband spectral states. These observations trace the source spectral evolution from the end-phase of activity driven by a new, additional HBL like emission component in 2017 to its complete disappearance in 2018 and re-emergence...
Tne of the main components of the Large High Altitude Air Shower Observatory (LHAASO) located in Daocheng, China. WFCTA detects cosmic rays by detecting photons generated by secondary particles of atmospheric showers. Changes in atmospheric depth in WFCTA's field of view will lead to changes in the number of photons in WFCTA. Therefore, the variation of atmospheric depth in the WFCTA is of...
The effect of thunderstorms’ atmospheric electric field on secondary cosmic rays (CR) detected at high altitude was studied. We analyzed the data obtained during the period of October 2019 to March 2020 by the Solar Neutron Telescope (SNT) and a Boltek EFM-100 electric field monitor installed in the Sierra Negra Cosmic Ray Observatory (SNCRO) located at 4580 m a.s.l. in Puebla, Mexico. Based...
The project Southern Wide-field Gamma-ray Observatory (SWGO) aims to build an array of air-shower detectors in the Southern hemisphere. Preliminary site searches identified suitable sites in Argentina, Bolivia, Chile and Peru. Site environment (including weather, seismic activity and also the electric field) is one of the key aspects to be considered in the site selection and should be based...
The three-dimensional distribution of both atomic and molecular gas in the Galaxy is a crucial modelling input, both for the generation of diffuse emission in gamma-rays and the transport of cosmic rays. Here, we present new 3D maps of molecular hydrogen based on the Dame et al. (2001) CO survey compilation. We consider the deprojection as a Bayesian variational inference problem. The...
The Southern Wide-field Gamma-ray Observatory (SWGO) is the project to build a new extensive air shower particle detector for the observation of very-high-energy gamma-rays in South America. SWGO is currently planned for installation in the Southern Hemisphere, which grants it a unique science potential among ground-based gamma-ray detectors. It will complement the capabilities of CTA, working...
In recent years, properties of the unresolved gamma ray background (UGRB) have been constrained by measuring the anisotropy in the form of the angular power spectrum (APS). The energy dependence of the anisotropy has been found to be consistent with a broken power law, suggesting the existence of two distinct source classes above and below $\sim$2 GeV. In this work, we aim to go beyond the...
The High-peaked BL Lac object 1ES 0647+250 is one of the few distant blazars detected at very-high-energy (VHE, E > 100 GeV) gamma rays during non-flaring activity. Its redshift is still uncertain, but a lower limit of z>0.29 was recently calculated, based on the minimum equivalent width of absorption features expected from the host galaxy. This blazar was first detected by the MAGIC...
Since their discovery, cosmic rays (CRs) remain among the most mysterious phenomena of modern physics. The dominant sources, as well as the exact acceleration mechanisms, remain unknown. The CRs up to the knee, are considered to originate in the shock waves of supernova remnants, however, due to the lack of a “smoking-gun” TeV counterpart in many cases, this scenario has been recently...
To probe physics beyond the scales of human-made accelerators with cosmic rays demands an accurate knowledge of their primary mass composition. Using fluorescence detectors, one is able to estimate this by measuring the depth of the shower maximum $X_\text{max}$. These, however, exhibit a very low duty cycle of typically below 15 %.
Inferring $X_\text{max}$ from a surface detector array...
HELIX (High Energy Light Isotope eXperiment) is a balloon-borne instrument designed to measure the chemical and isotopic abundances of light cosmic-ray nuclei. In particular, HELIX is optimized to measure 10Be and 9Be in the range 0.2 GeV/n to beyond 3 GeV/n. To achieve this, HELIX utilizes a 1 Tesla superconducting magnet with a high-resolution gas drift tracking system, time-of-flight...
EAS Cherenkov arrays are a powerful instrument for studies of primary cosmic rays in a wide range of energy. In this approach the Earth’s atmosphere is used as a calorimeter providing EAS Cherenkov arrays high energy resolution. Another advantage of the method is its high time resolution which results in a good angular resolution. Usually EAS Cherenkov array is a sparsely instrumented array...
The Cherenkov Telescope Array (CTA) is the next-generation gamma-ray observatory that is expected to reach one order of magnitude better sensitivity than that of current telescope arrays. The Large Size Telescopes (LSTs) have an essential role in extending the energy range down to 20 GeV. The prototype LST (LST-1) proposed for CTA was built in La Palma, the northern site of CTA, in 2018. LST-1...
Ab initio modulation models use a turbulence spectrum as input, and changes in this spectrum over multiple solar magnetic cycles can have significant effects on the calculated level of modulation. In this project, turbulence quantities are calculated for 27-day intervals and then binned and presented in 378-day intervals, using IMP and ACE magnetic field data from late 1973 to the last solar...
Thunderstorms are common weather phenomena at high altitudes, accompanying with lightning, strong winds, floods and other disasters. During thunderstorms, the strength of atmospheric electric fields could be up to 1000 V/cm or even higher. The intensity fluctuates violently and the polarity could change multiple times. So, direct measurement of the thunderstorm electric field is a quite...
We report the results and accompanying analysis methods from field-testing calorimeter prototypes for the Advanced Particle-astrophysics Telescope (APT) during the 2019 austral Antarctic balloon season and during a 2018 CERN beam test. The Advanced Particle-astrophysics Telescopeis a proposed space-based gamma- and cosmic-ray instrument that utilizes a novel dispersed imaging calorimeter for...
Underground laboratories (ULs) are now becoming more and more popular, not only for scientific reasons. However, they are still very important as potential dark matter search sites. Therefore, the idea was born to create a network of underground laboratories operating in the Baltic Sea region. The result was the BSUIN (Baltic Sea Underground Innovation Network) project and its current...
Nuclearites are SQM conglomerates that are hypothesized as possible candidates of macroscopic dark matter. When impacting the Earth’s atmosphere, they should undergo quasi-elastic collisions with the air molecules and emit black-body radiation, thus generating atmospheric luminous events similar to meteors. However, nuclearites could be distinguished from meteors mainly by their altitude,...
The IceCube Neutrino Observatory has observed a diffuse flux of astrophysical neutrinos with energies from TeV to a few PeV. Recent IceCube analyses are not sensitive to PeV neutrinos because their fluxes are attenuated by the Earth and the Extremely High Energy (EHE) result targets cosmogenic neutrinos only above 10 PeV. In this work, we present a new event selection that fills the gap...
The open-source Multi-Mission Maximum likelihood (3ML) Framework allows for the common analysis of diverse datasets. The ability to consistently fit and characterize astronomical data across many decades in energy is key to understanding the origin of the emission we measure with many different instruments. 3ML uses plugins to encapsulate the interfaces to data and instrument response...
A diffuse gamma-ray emission at $\sim$100 TeV can be expected as a result of the interactions of ultra-high-energy cosmic rays (UHECRs) with the cosmic microwave background (CMB) during their propagation. This radiation carries the information on the distribution of energetic sources and hence the cosmological evolution of the Universe. The GRAPES-3 is an extensive air shower (EAS) array,...
The DArk Matter Particle Explorer (DAMPE) is a satellite-borne experiment, in operation since 2015, aimed at studying high-energy gamma rays and cosmic nuclei fluxes. Of the various sub-detectors in the DAMPE payload, the Silicon-Tungsten tracKer-converter (STK) plays a significant role in the charge measurement of incoming ions. Depending on the angle of inclination of the impinging particle...
Plastic Scintillantor Detector (PSD) is part of DArk Matter Particle Explorer (DAMPE), which plays a crucial role of charge measurement for charged cosmic rays and acts as a veto for gamma rays. In this work, we give some updated correction methods to enhance the quality of charge measurement, especially for heavy nuclei. DAMPE has collected nearly 10 billions events by end of 2020, it has...
TeV DM candidates are gradually earning more and more attention within the community. Among others, extra-dimensional brane-world models may produce thermal DM candidates with masses up to 100 TeV, which could be detected with the next generation of very-high-energy gamma-ray observatories such as the Cherenkov Telescope Array (CTA).
In this work, we study the sensitivity of CTA to branon DM...
Active galactic nuclei (AGN), and the accompanied AGN jets, are some of
the most fascinating and luminous objects in the observable Universe.
Both the active cores and their jets are candidates for the engine of
cosmic rays, gamma rays, and neutrinos with the highest energies measured at Earth.
A deep understanding of the processes related to jets will not only
fuel the field of high...
Cosmological and astrophysical observations suggest that 85% of the total matter of the Universe is made of Dark Matter (DM).
However, its nature remains one of the most challenging and fundamental open questions of particle physics.
Assuming particle DM, this exotic form of matter cannot consist of Standard Model (SM) particles. Many models have been developed to attempt unraveling the...
Two radio spectrometer stations belonging to the e-CALLISTO network were installed in Peru by the Astrophysics Directorate of CONIDA. Given their strategic location near the Equator, it was possible to observe the Sun evenly throughout the whole year and the detector was unique in its time-zone coverage. The receiver located nearby the capital city of Lima took data in the metric and...
The first Large Size Telescope (LST-1) of the Cherenkov Telescope Array has been operational since October 2018 at La Palma, Spain, and its camera has been under commissioning. The camera of LST consists of 265 modules, each of which is equipped with 7 PMTs. An analog trigger system is implemented where PMT signals from 3 modules (21 pixels) are summed up before a discriminator. Upon the...
We present a few possibilities for forming an extended energy spectrum and producing a varied slope in different double-shock models. In our previous work, the converging double-shock model would provide more kinetic energy injecting into the particles acceleration. The high efficient injection rate excited by amplified magnetic turbulence from the converged region make the extended energy...
The KM3NeT Collaboration has successfully deployed the first detection units of the next generation undersea neutrino telescopes in the Mediterranean Sea at the two sites in Italy and in France. The data sample collected between December 2016 and January 2020 has been used to measure the atmospheric muon rate at two different depths under the sea level: 3.5 km with KM3NeT/ARCA and 2.5 km with...
This presentation will provide an overview of the art project Aganta Kairos (To Fish the Metaphysical Time). It celebrates the neutrino, the ghost particle, which is considered as a cosmic messenger by scientists, and as a link between people who care about their relationship to the cosmos and question their origins, for the artist. The artwork is based on a performance of celebration and...
After scattering off nuclei in the Sun, dark matter particles can be gravitationally captured by the Sun, accumulate in the Sun’s core and annihilate into Standard Model particles. Neutrinos originating from these annihilations can be detected by the IceCube Neutrino Observatory, located at the South Pole. Due to the non-observation of these neutrinos, constraints on the standard...
Axions and axion-like particles (ALPs) are thought to be produced along with Standard Model particles in a variety of astrophysical processes. Core-collapse supernovae (SNe) have been identified as a promising target to probe the existence of these hypothetical particles, which could make up at least a fraction of the universe's dark matter content.
The cumulative signal from all past SNe...
It is generally taken for granted that the observable Universe does not contain anti-matter objects or domains. Recently, the possible detection of anti-helium nuclei in cosmic rays by AMS-02 challenged this idea and reopened the debate on the existence of nearby reservoirs of antimatter, most plausibly in antistars. As antimatter domains surrounded by normal matter would produce a gamma-ray...
Simulating the radio emission of inclined extensive air showers for a ground based radio-antenna array we find a systematic displacement of the radio emission with respect to the Monte-Carlo shower impact point. We corrected the radio-emission footprint for the asymmetries due to the superposition of geomagnetic and charge-excess radiation as well as for the early-late effect. The remaining...
The General Antiparticle Spectrometer (GAPS) experiment is a balloon payload designed to measure low-energy cosmic antinuclei during at least three ∼35-day Antarctic flights, with the first flight expected in December, 2022. With its large geometric acceptance and novel exotic atom-based particle identification method, GAPS will detect ∼1000 antiprotons per flight and produce a precision...
We present the status of cosmic-ray detection activities at the Murchison Radio-astronomy Observatory. Using 128 antennas of the Murchison Widefield Array radio telescope in its extended configuration, we detect the radio emission from extensive air showers in the 122-154 MHz range at a rate of slightly less than once per hour, each with an approximate energy of 10^17 eV. We have developed a...
Atmospheric neutrinos are produced when cosmic rays interact with Earth’s atmosphere. The relationship between the cosmic ray spectrum and the neutrino spectrum is especially important around the cosmic ray all-particle knee. These energies correspond to the regime in which astrophysical neutrinos begin to dominate the neutrino flux, so accurate modeling of the cosmic-ray spectrum around the...
Using ground-based observations of cosmic rays (CR) from the World Network of Neutron Monitor Stations and a method of spectrographic global survey, we have examined variations in rigidity spectrum and galactic CR in November–December 2012.
The large-scale heliospheric current sheet (HCS), dividing the two hemispheres of the opposite magnetic polarities is a dominant large-scale feature of the Heliosphere and is known to play a crucial role in the modulation of anomalous and galactic cosmic rays (ACRs and GCRs)..
The present work investigates how the HCS may affect the acceleration of ACRs at the solar wind termination...
Parker’s transport equation stochastic solution for simulation cosmic rays distribution in the heliosphere is demanding on computing resources. Simulations can last days, weeks, or even months with certain input parameters. We implemented 1D Forward-in-time and Backward-in-time models for GPU with successful acceleration ranged from ~7x to 86x. This acceleration was gained with not a...
Recent cosmic-ray (CR) antiproton studies have claimed the possibility of an excess of data over the predicted flux at around 10 GeV, which can be the signature of dark matter annihilating into antiprotons. Nevertheless, this excess is subject to many uncertainties related to the evaluation of the antiproton spectrum produced from spallation interactions of CRs.
We implement a combined...
The solar disk is a bright gamma-ray source in the sky. The interactions of cosmic rays with the solar atmosphere produce secondary particles which can reach the Earth. In this work we present a comprehensive calculation of the yields of secondary particles such as gamma-rays, electrons, positrons, neutrons and neutrinos, performed with the FLUKA code. We also estimate the intensity at the Sun...
The detection of a PeV high-energy neutrino of astrophysical origin, observed by the IceCube Collaboration and correlated with a 3$\sigma$ significance with Fermi measurements to the gamma-ray blazar TXS 0506+056, further stimulated the discussion on the production channels of high-energy particles in blazars. Many models also consider a hadronic component that would not only contribute to the...
An air shower simulation package COSMOS was born in 1970’s and has been continuously developing. A recent major update enables particle tracking not only in the atmosphere but also in liquid and solid material by combining with the EPICS detector simulation package. This paper describes the properties of this extended version of COSMOS, namely COSMOS X. COSMOS X is coded using the FORTRAN...
The Cherenkov Telescope Array (CTA) will be the next generation gamma-ray observatory, which will consist of three kinds of telescopes of different sizes. Among those, the Large Size Telescope (LST) will be the most sensitive in the low energy range starting from 20 GeV. The prototype LST (LST-1) proposed for CTA was inaugurated in October 2018 in the northern hemisphere site, located in La...
The CSES space mission, an international collaboration between China and Italy, aims at monitoring the perturbations originated by electromagnetic emissions in the ionosphere, magnetosphere and in the Van Allen radiation belts, and at investigating possible correlations with seismic events. The Italian collaboration, named LIMADOU, contributed to the mission with the realization of the High...
The Cherenkov Telescopic Array (CTA), the next-generation ground-based gamma-ray observatory, will have unprecedented sensitivity in the very-high-energy gamma-ray regime, elucidating open questions in gamma-ray cosmology and fundamental physics. Using simulations of active galactic nuclei observations foreseen in the CTA Key Science Program, we find that CTA will measure gamma-ray absorption...
The pointing of Cherenkov telescopes is subject to imperfections which are, e.g. related to
the bending of the mechanical structure. These imperfections must be measured, modeled and finally corrected for to
achieve an optimal telescope pointing precision. The measurement of pointing deviations is typically
performed while the telescope points to different stars and a CCD camera
monitors...
Cosmic-ray positron measurements provide a powerful probe of dark matter annihilation. A possible contribution to the measured positron flux could come from dark matter annihilating or decaying into e+e- pairs. In this work, we combine a detailed scan of the cosmic-ray propagation parameter space using Galprop with a new time-, charge- and rigidity-dependent model for solar modulation to...
Experimental developments in neutrino telescopes are drastically improving their ability to constrain the annihilation cross-section of dark matter. In this talk we project the future sensitivity of a Neutrino telescope similar to KM3NeT. Focusing on particle models for dark matter, we assess how these future limits will complement the existing landscape of dark matter searches. This brings...
Silicon Micro-strip Detector (SMD) has been widely used in detecting charged particles. Using SMD as detector, and to measure the Linear Energy Transfer (LET) generated by the ionizing radiation in manned spacecraft, a prototype of LET spectrometer is designed. This paper presents the design of the data acquisition (DAQ) software for the LET spectrometer. To read out and preliminarily analyze...
Large High Altitude Air Shower Array ( LHAASO) is a large
hybrid EAS experiment located in Haizi Moutain, Daocheng, Sichuan
province of P.R.C . Water Cherenkov Detector Array (WCDA) is one
of subarrays aiming at VHE gamma ray astronomy. LHAASO-WCDA
has finished 2 pools installation and data-taking in the year of 2020.
Based on these data a lot of works and implementation have...
Galactic cosmic rays (GCRs) inside the heliosphere are affected by magnetic turbulence and Solar wind disturbances which result in the so-called solar modulation effect. To investigate this phenomenon, we have performed a data-driven analysis of the temporal dependence of the GCR flux over the solar cycle. With a global statistical inference of GCR data collected in space by AMS-02, PAMELA,...
Observations of high-energy astrophysical neutrinos in IceCube have opened the door to multi-messenger astronomy, by way of which questions in particle physics could be explored collaboratively between IceCube and optical experiments such as Fermi-LAT. However, the origin of these astrophysical neutrinos is still largely unknown. Among the tensions that still need to be resolved, for example,...
In this work we revise the estimate of dark matter (DM) decay signals from dwarf galaxies in the Milky Way. They are ideal for indirect DM searches, since they are known to be DM dominated systems. We test both warm and cold DM candidates, i.e., sterile neutrinos decaying into X-ray photons and a heavier DM candidate decaying into gamma rays.
We analyze the sensitivity to such a signal for...
We investigate the evolution of the afterglow produced by the deceleration of the non-relativistic material due to its surroundings. The ejecta mass is launched into the circumstellar medium with equivalent kinetic energy expressed as a power-law velocity distribution $E\propto \left(\Gamma\beta\right)^{-\alpha}$. The density profile of this medium follows a power law $n(r)\propto r^{-k}$,...
Deep learning algorithms have gained importance in astroparticle physics in the last years. They have been shown to outperform traditional strategies in particle identification, tracking and energy reconstruction.
The attractive feature of these techniques is their ability to model large dimensionality inputs and catch non-trivial correlations among the variables, which could be hidden or not...
Magnetic spectrometers detect the rigidity of charged particles by measuring the bending of their trajectories as they pass through a magnetic field. A novel magnetic spectrometer for an astroparticle physics experiment in space should have a maximum detectable rigidity of about 100 TV. This motivates the design of a toroidal spectrometer magnet with a bending strength of 3 T m. To facilitate...
The High Energy cosmic-Radiation Detection (HERD) is a future space experiment which will be installed on the China’s space station around 2025. The main goal of the experiment is the measurement of cosmic rays up to energies which are not explored by the instruments currently operating in space, in particular proton with energies up to PeV, nuclei up to hundreds of TeV per nucleon and...
The Cherenkov Telescope Array (CTA) is the next-generation ground-based observatory for very-high-energy gamma-ray astronomy. An innovative 9.7 m aperture, dual-mirror Schwarzschild-Couder Telescope (SCT) design is a candidate design for CTA Medium-Sized Telescopes. A prototype SCT (pSCT) has been constructed at the Fred Lawrence Whipple Observatory in Arizona USA. Its camera is currently...
Atmospheric muons can be used to image a volume due to multiple Coulomb scattering and absorption of different materials. This work presents the design and CORSIKA/Geant4 simulation of a prototype composed of an array of detectors. The detectors are based on plastic scintillators and silicon photomultipliers targeting new and cost-affordable technology. In order to image a volume we study the...
In this work we discuss ongoing development of a hybrid fiber optic/electrical data and timing infrastructure for the future IceCube Gen2 detector. The IceCube Neutrino Observatory is a kilometer-scale detector operating with 86 strings of modules. These modules communicate and transfer time stamps utilizing a custom protocol to mitigate the challenges of multi-kilometer cables such as signal...
Active galactic nuclei (AGN) are the most luminous and abundant objects in the γ-ray sky. AGN with jets misaligned along the line-of-sight (MAGN) appear fainter than the brighter blazars, but are expected more numerous. Fermi Large Area Telescope (LAT) detected 40 MAGNs compared to 1943 blazars. The aim of this study is to identify new MAGN candidates in the blazars of uncertain type (BCUs)...
Spectra in astroparticle physics are commonly approximated by simple power laws. The steeply falling nature of these power laws, however, makes the detection of additional components rather challenging. This holds true especially, if the additional components are small compared to the established ones. Energy spectra of muon neutrinos are an interesting example of such a scenario, where the...
The Schwarzschild-Couder Telescope (SCT) is a medium-sized telescope technology proposed for the Cherenkov Telescope Array. It uses a novel dual-mirror optical design that removes comatic aberrations across its entire field of view. The SCT camera employs high-resolution silicon photomultiplier (SiPM) sensors with a pixel size of 4 arc minutes. A prototype SCT (pSCT) has been constructed at...
We present the method used to estimate the cosmic-ray observations expected for that the Trans-Iron Galactic Element Recorder for the International Space Station (TIGERISS), which is designed to measure the abundances of the rare Ultra-Heavy Galactic Cosmic Rays (UHCR) $_{30}$Zn and heavier. TIGERISS uses planes of crossed silicon strip detectors at the top and bottom for charge and trajectory...
Neutron monitors (NM64) are ground-based cosmic ray detectors that measure the flux of primary cosmic rays at the GeV-energy range by counting (primarily) secondary neutrons in atmosphere cascades. They have a lead producer to generate evaporation neutrons that are moderated before being detected in a $^{10}BF_{3}$ or $^{3}He$ gas-filled proportional counter. By omitting the lead, a so-called...
While the quest of searching for the origins of the most energetic cosmic rays and the associated dynamics continues, there is a growing interest in recent years of the use of the cosmic rays for practical applications following the advancement of particle detection technologies. One of these important applications is to study the correlations between the cosmic ray flux variations and the...
The mission CSES (China Seismo-Electromagnetic Satellite) will put into orbit satellites to study perturbations in the ionosphere, possibly correlated with the occurrence of seismic events. CSES-02, the second satellite of the constellation, will be supplied with a High-Energy Particle Detector (HEPD), composed by a tracker, a trigger system and a calorimeter, designed for the detection of...
Development of instruments capable of detecting gamma rays across vast ranges of energies is important for understanding different astrophysical objects. Instruments are constrained by cost, power, autonomous operation and sensitivity over wide range of energies. Photomultiplier tubes have been the main photon detection technology for these experiments because they can be manufactured in large...
Dark photon arises as the extra gauge boson in a U(1) Standard Model extension and it couples to ordinary photon via kinetic mixing. The parameter space spans many orders of magnitude in energy and has been explored widely by terrestrial and astrophysical measurements. In this work, we focused on development of a detector system to study a narrow energy band from 7-8 eV motivated by other...
We describe two test benches that were designed and constructed to perform a set of acceptance tests for about 1200 Photomultiplier Tube (PMT) units to be operated in the surface scintillation detectors of AugerPrime. Besides robustness, long-term reliability, and low power consumption, the dynamic range of the PMT-unit is required to cover signals ranging from a single to more than 20,000...
Fast neutrons ( > 0.5 MeV) are ubiquitous in nature, originating from nuclear interactions in environments including the solar corona, within planetary atmospheres, and in the lunar regolith. However, measurements of fast neutrons of solar origin are extremely limited due to the challenges imposed by high backgrounds and the relatively short lifetime of free neutrons before they undergo beta...
Ground-based neutron counters are a standard tool for detecting atmospheric showers from GeV range primary cosmic rays of either solar or galactic origin. Bare neutron counters, a type of lead-free neutron monitor, function much like standard neutron monitors but have different yield functions primarily because they are more sensitive to neutrons of lower energy. When operated together with...
The Outreach Cosmic Ray Activities (OCRA) project offers a platform for all outreach activities focusing on cosmic rays within the Italian Istituto Nazionale di Fisica Nucleare (INFN). Created in 2018, OCRA now counts 21 of the institute’s divisions all over Italy as members. The project’s core activity is the participation of all its members in the International Cosmic Day, organized by DESY,...
IceTop, the surface array of IceCube, measures air showers from cosmic rays within the energy range of 1 PeV to a few EeV and a zenith angle range of up to ≈ 36°. This detector array can also measure air showers arriving at larger zenith angles at energies above 20 PeV. Air showers from lighter primaries arriving at the array will produce fewer muons when compared to heavier cosmic-ray...
We study the impact of electromagnetic conditions in the Sun, in interplanetary space and the Earth's magnetosphere ( that is the so-called space weather) on possible disturbances with radar work and loss of communication with aircraft on the air traffic control tower (ATC) of the military airport in Dęblin.
At the beginning, the period of maximum solar activity in 2014 was examined
An...
In addition to solar modulation according to the ~11-year sunspot cycle and the ~22-year solar magnetic cycle, the time profile of the Galactic cosmic ray flux can also exhibit short-term (~2-week) modulation events. These are distinct from Forbush decreases in that they are more symmetric in time and are not associated with the local passage of an interplanetary shock and/or coronal mass...
The Southern Wide-field-of-view Gamma-ray Observatory (SWGO) will use the well-established and cost-effective technique of detecting Cherenkov light produced in water-filled detection units for TeV gamma-ray astronomy. Leveraging detector material reflectivity together with optimised aspect-ratio is an option to improve the performance of an array of such detector units. The double-layered...
While the KM3NeT neutrino detector is currently being deployed in the Mediterranean Sea, the Collaboration has been searching for illustrations of the neutrinos it will detect. The participants to the contest were invited to submit their best interpretation of a neutrino using any technique or support. Each neutrino flavour corresponded to a different age category.
More than 500 drawings...
Silicon Photomultiplier SiPM detectors have become the preferred photosensors for many applications in high-energy particle and astroparticle physics, LIDAR and medical imagining. Due to robustness, low working voltage, ability to work during moon light and high photon detection efficiency the SiPM devices are good choice for cameras of Imaging Atmospheric Cherenkov Telescopes (IACTs) as...
Cherenkov telescope cameras are not suitable to perform astrometrical pointing calibration since they are not designed to produce images of the sky, but rather to detect nanosecond atmospheric flashes due to very high-energy cosmic radiation. Indeed, these instruments show only a moderate angular resolution (fractions of degrees) and are almost blind to the steady or slow-varying optical...
The adoption of pixel sensors for space-based tracking detectors requires low power consumption and enhanced heat dissipation to cope with the satellite power and cooling constraints. The High Energy Particle Detector (HEPD) tracker onboard the CSES-02 will be the first application of monolithic active pixel sensors (MAPS) to a satellite-based experiment. This result is achieved with a...
Starting in summer 2021, the Radio Neutrino Observatory Greenland (RNO-G) will search for cosmic neutrinos with energies above 10PeV by detecting Askaryan radio emission from particle showers in the ice of Greenland. It will consist of 35 independent detector stations, each featuring 24 antennas deployed up to a depth of 100m. To cover a large volume, stations are spaced over 1km apart, so...
The recent progress in the radio detection technique for air showers paves the path to future cosmic-ray radio detectors. Digital radio arrays allow for a measurement of the air-shower energy and depth of its maximum with a resolution comparable to those of the leading optical detection methods. One of the remaining challenges regarding cosmic-ray radio instrumentation is an accurate...
The TUS observatory, as a part of the JEM-EUSO program, aimed at the detection of Ultra High Energy Cosmic Rays (UHECR). TUS was the first UHECR detector to operate in space and was launched on April 28th 2016 from the Vostochny cosmodrome in Russia. It operated until December 2017 and collected ~80000 events with a time resolution of 0.8 μs. A fundamental parameter to be determined for the...
Photons in the EeV range and beyond are expected from top-down models of UHECR production and from the GZK effect. As they reach the Earth, they have a non-zero probability of converting into an electron/positron pair in the geomagnetic field and producing an electromagnetic shower above the atmosphere. In this paper, we present a new method to search for cascading UHE photons with gamma-ray...
The measurement of the mass composition of ultra-high energy cosmic rays constitutes one of the
biggest challenges in astroparticle physics. Most detailed information on the composition
can be obtained from measurements of the depth of maximum of air showers, $X_\mathrm{max}$, with the use of fluorescence telescopes, which can be operated only during clear and moonless nights.
Using deep...
Recent results from IceCube regarding TXS 0506+056 suggest the presence of neutrino flares that are not temporally coincident with a significant corresponding gamma ray flare. Such flares are particularly difficult to identify, as their presence must be inferred from the temporal distribution of neutrino data alone. Here we present the results of using a novel method to search for all such...
Electron fluxes with energies of 3-30 MeV were analyzed using data from the ARINA satellite experiment. The changes in the spectrum of high-energy electrons in March 2012 were analyzed.
Signal estimation in the presence of background noise is a common problem in many scientific disciplines. An “On/Off” measurement is when the background itself is imprecisely measured, which is the case for instance of observations performed in astronomy. The ‘frequentist’ and Bayesian approaches for signal estimation in “On/Off” measurements are reviewed and compared, focusing on the...
The AugerPrime Radio Detector will significantly increase the sky coverage of mass-sensitive measurements of ultra-high energy cosmic rays with the Pierre Auger Observatory. The detection of highly inclined air showers with the world’s largest 3000 km$^2$ radio-antenna array in coincidence with the Auger water-Cherenkov detector provides a clean separation of the electromagnetic and muonic...
The Extreme Universe Space Observatory Super Pressure Balloon 2 (EUSO-SPB2) is under development, and will prototype instrumentation for future satellite-based missions, including the Probe of Extreme Multi-Messenger Astrophysics (POEMMA). EUSO-SPB2 will consist of two telescopes. The first is a Cherenkov telescope (CT) being developed to identify and estimate the background sources for future...
The High Energy Particle Detector (HEPD) is one of the scientific payloads of the China Seismo-Electromagnetic Satellite (CSES). The first satellite of the constellation was launched in February 2018 and has been operational in nominal conditions since then. With the launch of the CSES-02 scheduled for mid 2022, the realisation of the HEPD-02 detector is ongoing.
The Limadou collaboration, in...
The core-collapse supernova (CCSN) SN1987A has been the first extragalactic transient source observed in neutrinos, and the 25 events detected by the neutrino telescopes running at the time marked the beginning of neutrino astronomy. Despite the very large number of CCSNs detected in the electromagnetic spectrum since 1987, neutrino telescopes could not perform another observation due to the...
I present the results of variability study of a sample of 20 powerful blazars using Fermi/LAT (0.1-300 GeV) observations. We studied decade-long observations applying various analysis tools such as flux distribution, symmetry analysis, and RMS-flux relation. It was found that the γ-ray flux distribution closely resembles a log-normal probability distribution function and can be characterized...
We present a method based on the use of Recurrent Neural Networks to extract the muon component from the time traces registered with water-Cherenkov detector (WCD) stations of the Surface Detector of the Pierre Auger Observatory. The design of the WCDs does not allow one to separate, for all events, the contribution of muons to the time traces from those of photons, electrons and positrons....
The ASTRI Mini-Array is a system of nine imaging atmospheric Cherenkov telescopes to be deployed at the Observatorio del Teide (Tenerife, Spain). In a first phase, the instrument will be operated as an experiment, with an observation schedule focused on primary science cases at multi-TeV energies (origin of cosmic rays, cosmology and fundamental physics, GRBs and multi-messenger astrophysics)....
Back in mid 2018, we were organizing Extreme19, a conference on astro-particle physics held in Padova on the topic of extremely energetic emission from galaxies. For the preparation of the graphical material in support of the conference we seeked for a collaboration with talented art students. To this purpose, we joined the Italian programme ‘PCTO’ (percorsi per le competenze trasversali e...
Determination of the nature and sources of ultrahigh energy cosmic rays (UHECR, E>10^{18} eV) is still unsolved problem in cosmic ray physics. The observed high degree of UHECR isotropy, caused mainly by the deviations of the UHECR trajectories in extragalactic and Galactic magnetic fields, together with a significant uncertainty in their chemical composition (atomic mass), don’t allow...
The First G-APD Cherenkov Telescope (FACT) is a telescope located at the Observatory Roque de los Muchachos on the Canary island La Palma. It uses the imaging air Cherenkov technique to detect gamma rays. With the help of the silicon based photosensors of the camera, FACT is a perfect instrument to monitor a small sample of sources with a high cadence. The automatic operation of the telescope...
M87 is one of the nearest radio galaxy. We can study the core, jet, and some components by radio to X-ray observations.
Regarding TeV gamma ray observations, it is known to show an intra-day variability.
Such fast variability may occur at the particle acceleration region. But due to rough angular resolution, we cannot know which component causes this variability.
We searched for fast...
Air showers induced by cosmic protons and heavier nuclei constitute the dominant background for very high energy gamma-ray observations of Imaging Air Cherenkov Telescopes (IACTs). Even for strong very high energy gamma-ray sources the signal-to-background ratio in the raw data is typically less than 1:5000. Therefore, a very large statistic of events, induced by cosmic protons and heavier...
The Borexino experiment has recently provided the first direct experimental evidence of the sub-dominant CNO-cycle in the Sun, which is assumed to be the main energy production mechanism in heavier stars. Borexino is a liquid scintillator detector located at the Laboratori Nazionali del Gran Sasso, Italy with the main goal to measure solar neutrinos. The extreme radiopurity of the scintillator...
The NEMESIS experiment (New Emma MEasurement with neutronS In cosmic Showers)
is located in Pyhasalmi Mine (Finland), and operates at a depth of 75 m (210 m.w.e.),
corresponding to 50 GeV cutoff energy for vertical muons.
The experiment consists of a pixelized (11cm x 11cm) scintillation
telescope, 14 helium counters, 2 1m^2 scintillating detectors,
and Pb target. The...
KM3NeT is a Cubic Kilometer Neutrino Telescope that is currently being constructed at the bottom of the Mediterranean Sea. The KM3NeT/ORCA detector will be used for oscillation physics with atmospheric neutrinos, with as main goal establishing the neutrino mass ordering.
In 2019, 4 out of the total of 115 vertical lines carrying the light sensors of the ORCA detector had been deployed,...
TRAGALDABAS is a high performance, high granularity, tracking detector of the Trasgo family. It is installed at the Univ. of Santiago de Compostela (42.876N, 8.560W), Spain. The detector is based on the RPC technology (Resistive Plate Chamber) offering a surface of 1.8m2 with granularity of 120 cells, multitracking capability, time resolution of ~0.4ns, an angular resolution close to 3º and...
The High Energy cosmic-Radiation Detection (HERD) facility is a space payload proposed to be installed onboard the China’s Space Station (CSS). The aim of HERD is the direct detection of cosmic rays towards the “knee” of the spectrum (~ 1 PeV) and the monitoring of the gamma ray sky up to 1 TeV. The HERD core is a calorimeter capable of accepting particles incident on its top and four lateral...
The experiments PAMELA and AMS-02 measured an anomalous local positron excess above energies of 10 GeV. The reason for this excess is not well understood but has been considered as indirect evidence of dark matter, but could also be produced from nearby pulsars. The HAWC collaboration previously studied the extended gamma-ray emission of two nearby pulsars, Geminga and PSR 0656+14, but found...
High-energy particles undergo different interactions while propagating through the Universe. As a result, they initiate particle cascades of various types and sizes, referred to as
cosmic-ray ensembles (CRE). Since recently, Cosmic-Ray Extremely Distributed Observatory
(CREDO) Collaboration aims at pursuing a mission dedicated to CRE, since this observation
channel, i.e. correlated...
The expected low background of light antinuclei, such as antideuteron and antihelium-3, make them ideal detection channels for exotic physics, such as dark matter annihilations. At the same time, their small binding energies and composite structures make them promising probes for the QCD phase diagram in heavy ion collisions. In order to correctly interpret experimental data, however, a solid...
The Southern Wide-field Gamma-ray Observatory (SWGO) is a proposed experiment that will continuously monitor the TeV gamma-ray sky. Similar to the High Altitude Water Cherenkov (HAWC) Observatory, is will have a wide field of view, nearly 100% duty cycle, and will therefore observe ~2/3 of the sky every day. It will use water cherenkov detectors and be located in the southern hemisphere. SWGO...
The Ashra-1 detector has been developed to efficiently take fine images of air-shower (AS) Cherenkov (CE) and fluorescence (FL) light induced by the Earth-skimming $\nu_{\tau}$ and $\gamma$-ray ASs. Based on Ashra-1, we have planned a new extension, i.e. Neutrino Telescope Array (NTA), an AS imaging $\nu$ and $\gamma$-ray observation system for "Clear Discovery and Identification of...
We study the galactic cosmic ray modulation in the heliosphere based on Australian muon telescopes data. We analyze the modulation parameters of galactic cosmic ray transport in the heliosphere retrieved from GCR anisotropy for solar cycle 24 covering the period 2006-2018.
We use the Fourier analysis and wavelet methods to study the periodicity in the GCR intensity and anisotropy. We...
Secondary positrons produced inside Galactic Molecular Clouds (GMCs) can contribute significantly to the observed positron spectrum on earth. Multi-wavelength data on GMCs are particularly useful to build this model. Very recent survey implemented the optical/IR dust extinction measurements, to trace 567 GMCs within 4 kpc of Earth, residing in the Galactic plane. We use the updated list of...
The ASTRI-Mini Array will be composed of nine imaging atmospheric Cherenkov telescopes
at the Teide Observatory site. The array will observe in the 1-200 TeV range with an
angular resolution of few arc-minutes and an energy resolution of about 10%.
A core-science programme will be devoted in the first three years to
a limited number of key science targets. Additionally, thanks to a...
The Tibet air shower (AS) array and underground water-Cherenkov-type muon detector (MD) array have been successfully operated since 2014, at an altitude of 4,300m in Tibet, China. The gamma-ray energy and arrival direction are determined by the Tibet AS array, while the MD array enables us to suppress more than 99.9% of background cosmic rays above 100 TeV, by means of counting the number of...
We present the analysis of 9.7 years Fermi-LAT data of the middle-aged supernova remnant (SNR) W44 and the massive molecular gas complex that surrounds it. The derived spectral energy distribution of the SNR, derived over three decades is improved, with respect to previous observations, both at low (< 100 MeV) and at higher energies (> 100 GeV) allowing us to strongly constrain the hadronic...
The Southern Wide-field Gamma-ray Observatory (SWGO) is the next-generation gamma-ray observatory, currently in a three-year R&D phase. The experiment is expected to have a large array of water Cherenkov detectors (WCD) placed at a high elevation (> 4.4 km a.s.l.) in South America. Here we present a WCD concept with reduced surface area and height stations comprising four PMTs at the bottom....
Axions and axion-like particles (ALPs) are hypothetical particles that occur in extensions of the Standard Model and are candidates for cold dark matter. They could be detected through their oscillations into photons in the presence of external electromagnetic fields. gammaALPs is an open-source python framework that computes the oscillation probability between photons and axions/ALPs. In...
Atmospheric conditions affect the development of secondary particles produced by primary cosmic rays. In this work, we present a methodology to simulate the impact of the Global Data Assimilation System (GDAS) atmospheric models in secondary particle flux at the Earth's surface. GDAS implements global atmospheric models based on meteorological measurements and numerical weather predictions....
Solar originating events are continually evident in galactic cosmic ray (GCR) flux registered at the ground by neutron monitors and in situ by space probes. We analyze time intervals of sporadic Forbush decreases during the ascending phase of solar cycle 24. We consider cosmic rays flux, as well as, solar, heliospheric and geomagnetic activity parameters, around these periods, using different...
Markarian 421 is a high-synchrotron-peaked blazar showing relentless variability across the electromagnetic spectrum from radio to gamma-rays. We use 5 years of radio and GeV observations to study the correlation and connected variability in radio and GeV bands. Radio data was obtained in a 15GHz band by the OVRO 40-m radio telescope and GeV data is from Fermi Large Area Telescope. To...
Optical photons, created from fluorescence or Cerenkov emission in atmospheric cascades induced through high energetic cosmic rays are of major interest for several experiments. Experiments like CTA require a significant amount of computing time and funds for the simulation with CORSIKA.
Since individual photons don't interact they can be simulated without any order as in the traditional...
While the youngest known supernova remnants (SNRs), such as Cas A, have been proven to be able to accelerate CRs only up to $\sim 10^{14}\,\mathrm{eV}$, recent studies have shown that particle energies larger than a few PeV ($10^{15}\,\mathrm{eV}$) could actually be reached during the early stages of a core-collapse Supernova (cc-SN), when the high-velocity forward shock expands into the dense...
Theoretical atmospheric neutrino flux estimates serve as a crucial input for the determination of the neutrino mass hieararchy, the unitarity of the PMNS matrix and the atmospheric mixing angle $\theta_{23}$ in underground neutrino detectors, such as the Super-Kamiokande, IceCube DeepCore and KM3Net ORCA. With the expected reduction of detector-induced systematic uncertainties by the IceCube...
ALPACA is a project aimed at the wide field-of-view observation of cosmic rays and gamma rays with an 83,000 m^2 air shower array composed of approximately 400 surface scintillation counters and a large underground muon detector array, at an altitude of 4,740m near the Chacaltaya mountain in Bolivia. After a prototype air-shower array currently under construction, we plan to expand the array...
Precise studies of solar energetic particles provide an important basis to understand their acceleration and propagation in the interplanetary space. A specific interest is paid to solar protons possessing with energy high enough to induce an atmospheric cascade in the Earth’s atmosphere, whose secondary particles can reach the ground, being eventually registered by ground-based detectors e.g....
When cosmic-ray arrival directions are observed in celestial coordinates, they appear to have a small anisotropy whose origin is still largely unknown. In addition to this celestial anisotropy, the Earth's revolution around the Sun produces a faint Compton-Getting dipole anisotropy with an excess oriented towards the direction of motion in solar coordinates. The relative rotation of the...
Cosmic radiation is a critical factor for astronauts’ safety in the context of evaluating the prospect of future space exploration. The Radiation Assessment Detector (RAD) on board the Curiosity Rover launched by the Mars Scientific Laboratory mission collected valuable data to model the energetic particle radiation environment inside a spacecraft during travel from Earth to Mars, and is...
Pohl et al. (2008) used a gas-flow model based on a SPH simulation to deconvolve Galactic CO data. They employed an iterative method to successively reduce signal in the line spectrum and place it at the eight best-matching distance intervals, until there is only noise left. In Macias et al. (2018) an analogous deconvolution of HI data was found to provide a better fit to the diffuse gamma-ray...
The Coma Cluster of Galaxies (at z=0.023) is one of the largest gravitationally-bound astrophysical structures in the local Universe (linear size of more than 2 Mpc). Considering the proximity of Coma in addition to the relatively large intracluster density and the high-velocity accretion shocks (estimated speed of 2-3 thousand km/s) that occur within-cluster, it provides a unique environment...
Since the deployment of the CALorimetric Electron Telescope (CALET) on the exposure facility of the Japanese Experiment Module (JEM) 'Kibo' of the International Space Station in 2015, CALET is accumulating cosmic ray data steadily without any serious faults up to now. Although CALET is basically a high-energy cosmic-ray detector, its composite and thick detector structure allow us to separate...
IceCube is a cubic kilometer neutrino detector array in the Antarctic ice that was designed to search for astrophysical, high-energy neutrinos. It has detected a diffuse flux of astrophysical neutrinos that appears to be of extragalactic origin. A possible contribution to this diffuse flux could stem from core-collapse supernovae. The high-energy neutrinos could either come from the...
Measuring the fluxes of ultra-high energy cosmic rays is a unique tool for studying and testing physics beyond the standard cosmological and elementary particle interaction models. The observation of their fluxes above PeV is of particular interest, since the detection of extensive air-showers produced by these particles allows testing the energy range that is beyond the reach of modern...
Neutron-induced interactions contribute to the signal-mimicking background in deep-underground searches for exotic phenomena such as Dark Matter, neutrino-less double beta decay, proton decay, etc. Apart from radioactive decay, the primary source of neutrons underground are high-energy muons from cosmic showers. While the maximum number of fission neutrons is around six and energies around one...
We will present a conceptual design for an Imaging Calorimeter for space instruments based on a 3-dimensional position-sensitive virtual Frisch-grid CdZnTe (CZT) detectors. The calorimeter aims to measure photons with energies from 50 keV to 20 MeV with energy resolution of < 1% FWHM at 662 keV, and the photon interaction sites location accuracy of <1 mm in all 3 dimensions. Each detector is a...
IceAct is a proposed surface array of compact (50 cm) and cost-effective Imaging Air Cherenkov Telescopes installed at the site of the IceCube Neutrino Observatory at the geographic South Pole. Since January 2019, two IceAct telescope demonstrators, featuring 61 silicon photomultiplier (SiPM) pixels have been taking data in the center of the IceTop surface array during the austral winter. We...
A twin detector of ORCA, the cosmic ray detector operating at Juan Carlos I Spanish Antarctic Base, is foreseen to be installed at Izaña Atmospheric Observatory (IZO) during the second part of 2021. IZO belongs to the State Meteorological Agency of Spain (AEMET) and it is located at the top of a mountain plateau in Teide volcano at Tenerife Island (28º18’N, 16º29’W, 2373 m a.s.l.) at...
While gradient and curvature drifts are well-established elements of
the propagation of cosmic rays in the heliospheric magnetic field,
their perturbation by the solar activity-induced large-scale
distortions of dipole-like field configurations even during solar
minima and by magnetic turbulence is an open problem. Various
empirical or phenomenological approaches have been suggested...
Ultra-high energy cosmic rays (UHE CRs) interacting with the cosmic radiation background produce two cosmogenic messengers: neutrinos with energies in the EeV range and gamma rays accumulating in the GeV-TeV range. The most optimistic scenario for cosmogenic fluxes assumes the dominance of protons above the Greisen-Zatsepin-Kuzmin threshold of resonant scattering with photons in the cosmic...
Homemade antipersonnel mines are improvised explosive devices (IED) deployed from unconventional local techniques and materials. IEDs kill thousands of civilians every year, inflicting grievous physical injuries, spreading fear and disruption across affected communities. Colombian mines, made of a combination of ammonium nitrate and fuel oil known as ANFO, may also pack faeces, glass, and...
The Sun is a possible target for indirect dark matter (DM) searches, as it can gravitationally capture DM particles from the Galactic halo, which can be trapped in external orbits or sink into the solar core. We have performed a dedicated analysis of solar gamma rays collected by the Fermi Large Area Telescope (LAT) to search for possible flux excesses, which could be ascribed to DM. Gamma...
Even though there are strong astrophysical and cosmological indications to support the existence of dark matter, its exact nature remains unknown. We expect dark matter to produce standard model particles when annihilating or decaying, assuming that it is composed of Weakly Interacting Massive Particles (WIMPs). These standard model particles could in turn yield neutrinos that can be detected...
The Latin American Giant Observatory (LAGO), operates an extensive network of Water Cherenkov Detectors (WCD) by a non-centralized and collaborative network of Universities and Research Institutes in Iberoamerica. To estimate the charge distribution produced by secondaries particles interacting with WCDs, LAGO developed a simulation framework (ARTI). ARTI comprises a chain of simulations...
Due to their large mirror size, fast response to single photons, sensitivity and telescope baselines in the order of 100 m, Imaging Atmospheric Cherenkov Telescopes are ideally suited to make intensity interferometry observations. In 2019 a test readout setup was installed in the two 17-m diameter MAGIC telescopes to allow performing interferometry measurements with them. The first on-sky...
Extreme High-frequency-peaked BL Lac (EHBL) objects, a subclass of blazars characterised by a synchrotron peak frequency exceeding 10^17 Hz, and, in some cases, an inverse Compton peak energy exceeding 1 TeV, are ideal sources to study the InterGalactic Magnetic Field (IGMF) due to the hardness of their spectrum. HESS J1943+213 is a Very High Energy (VHE, >100 GeV) γ-ray source shining through...
Astronomical events such as Solar and Lunar eclipses provide the opportunity for studying the disturbance produced in the atmosphere by these events and its effect on cosmic ray intensity. There are earlier reports on decrease in secondary cosmic gamma ray (SCGR) flux during solar eclipse and enhancement of the same during lunar eclipse. We present the results from the measurement of SCGR...
Blazars have very complex variability properties. They sometimes exhibit multi-wavelength and other times "orphan" flares in specific wavelength. Different models have been proposed to explain specific flares. In this paper, we propose a unified model to explain different blazar flares in the same framework naturally. We consider a model in which the emission of a blazar consists of two...
The origin of high-energy neutrinos, observed in the last 10 years by IceCube, is unknown. We gain more insight by studying the expected angular distribution of potential source populations, considering that IceCube observes a neutrino sky consistent with an isotropic distribution.
We simulate neutrino skymaps by applying statistical distributions for the fluxes of extra-galactic sources and...
There has been a recent discovery of an excess in the gamma ray emission from the Andromeda Galaxy (M31) observed with the Fermi Large Area Telescope. The origin of this excess, however, is completely unknown. The goals of this work are (1) to show that the excess is indeed real and not due to improper treatment of the back-/foreground models; (2) to analyze the morphology and spectrum of the...
Cosmic Ray Ensembles (CRE) are very large, yet not observed particle cascades initiated above the Earth atmosphere. Such cascades could be formed both within classical models (e.g. products of photon-photon interactions) and exotic scenarios (e.g. result of decay of Super Heavy Dark Matter particles and subsequent interactions). Some of CRE might have a significant spatial extent which could...
The goal of the ISS-CREAM experiment is to measure spectra of cosmic-ray particles up to 1000 TeV from protons to iron nuclei. The detector was designed to complement other current space-based cosmic-ray missions, and was installed on the ISS on August 22, 2017. During 539 days of on-orbit operations, ISS-CREAM recorded over 58 million events. The instrument consists of a 4-layer silicon...
The KM3NeT Collaboration is currently building a neutrino observatory at the bottom of the Mediterranean Sea. The telescopes are equipped with thousands of Digital Optical Modules hosted in glass spheres, instrumenting a volume of several cubic kilometers. The acquisition electronics is housed inside the glass sphere performing the readout of the 31 PMTs of the Digital Optical Module. In the...
The KM3NeT research infrastructure in the Mediterranean is a multi-purpose cubic-kilometer neutrino observatory consisting of two detectors optimized to study cosmic and atmospheric neutrinos between GeV to PeV energies. Additionally, KM3NeT multi-photomultiplier optical modules allow the detection of nearby MeV interaction products by selecting nanosecond coincidences within the...
The KM3NeT neutrino telescope, currently under construction, consists of two detectors in the Mediterranean Sea, ORCA and ARCA, both using arrays of optical modules to detect the emitted Cherenkov light from charged particles created in neutrino interactions. Although originally designed for neutrino oscillation and astrophysical research, this experiment also bears unprecedented possibilities...
The KM3NeT collaboration is constructing a km3 volume neutrino telescope in the Mediterranean sea, called ARCA (Astroparticle Research with Cosmics in the Abyss), that will achieve an unprecedented sensitivity to high-energy cosmic neutrinos. This telescope will be able to reconstruct the arrival direction of the neutrinos with a precision of ~0.1 degrees. The configuration of ARCA makes it...
Southern Wide-field Gamma-ray Observatory (SWGO) will be a next-generation high altitude gamma-ray survey observatory in the southern hemisphere consisting of an array of water cherenkov detectors. With its energy range, wide field of view, large duty cycle, and location it will complement the other existing and planned gamma-ray observatories. In this contribution, we will describe the lake...
The possibility of antihelium production in interaction of cosmic rays with the interstellar gas is studied using large-scale Monte Carlo simulations. For this purpose, an energy-dependent coalescence mechanism developed previously is extended to estimate the production of light antinuclei (antihelium-3 and antihelium-4). The uncertainty in the coalescence parameter and its effect on the...
KASCADE-Grande was a cosmic ray experiment located at the Karlsruhe Institute of technology (110 m a.s.l., 49°N, 8°E), Germany, and it was designed to study extended air showers (EAS) initiated by primary nuclei in the energy range between 10 PeV and 1 EeV. KASCADE-Grande was capable of measuring the local density of charged particles, muons and of electrons of the EAS at ground level using...
The Daya Bay Reactor Neutrino Experiment, located in southeast China, was designed to measure short baseline oscillation of electron antineutrinos originating from six 2.9 GWth nuclear reactors. Since 2011, it has collected an unprecedented sample of millions of reactor antineutrino candidates, the largest sample in the world up to date, which led to the discovery of the non-zero...
The PolarquEEEst scientific programme consists in a series of measurements of the cosmic ray flux up to the highest latitudes, well beyond the Polar Article Circle. It started in Summer 2018, when one telescope for cosmic rays was installed on a sailboat leaving from North Iceland, to circumnavigate the Svalbard archipelago and land in Tromsø. It collected data up to 82N, measuring with...
Neutrino Non Standard Interactions (NSI) are one of the sub-dominant effects which can affect neutrinos propagating through matter via observable changes in their oscillation patters predicted by the standard oscillation parameters. These interactions should modify neutrino flavour ratio observed in neutrino telescopes measuring atmospheric neutrino flux.
The ANTARES neutrino telescope has...
NA61/SHINE is a large-acceptance fixed-target experiment located at the CERN SPS, which studies final hadronic states in interactions of various particles and nuclei. It is unique in terms of providing data on a variety of collision systems at different collision energies. This allows for wide deuteron, antiproton and antideuteron production cross-section studies. The latter are currently...
In addition to dense regions of dark matter, such as galaxy clusters and dwarf galaxies, dark matter annihilation and decay are also expected to have a nearly isotropic distribution across the sky. This isotropic component is less model-dependent than the flux from isolated dark matter targets, and would produce both galactic and extra-galactic contributions to the Diffuse Gamma-Ray Background...
The high-energy Diffuse Gamma-Ray Background (DGRB) is expected to be produced by unresolved extra-galactic objects such as active galactic nuclei and isotropic Galactic gamma rays. At TeV energies, observations or stringent limits on the DGRB could have significant multi-messenger implications, such as constraining the origin of TeV-PeV astrophysical neutrinos detected by IceCube. With its...
The existence of heavy compact objects has been suggested many times throughout the years. In terms of sizes, they would belong to the realms of nuclear or atomic physics, but in terms of masses could extend to the macroscopic world, reaching kilograms, tones or more. The most notable candidates are nuclearites - hypothetical lumps of strange quark matter, Q-Balls, magnetic monopoles or...
The ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) Mini-Array project is a wide international effort led by the Italian National Institute for Astrophysics aiming at operating an array of nine ASTRI Cherenkov telescopes. The Mini-Array will operate in the energy range 1-100 TeV and beyond and will be dedicated to very high-energy gamma ray astrophysics and optical intensity...
The search for long-range correlations among air showers is one of the main goal of the Extreme Energy Events (EEE) Project. The existence of such events has only been supposed theoretically through several physical mechanisms, the most convincing being the so-called GZ effect, based on the photodisintegration of a heavy primary nucleus in the solar field. Even with a large detector coverage...
Water scarcity is a significant challenge for the world’s population. With the likelihood of extreme droughts increasing each year, technologies to promote sustainable irrigation and improve resilience to water shortage are needed. Continuous monitoring of soil moisture in arid regions is a major problem as existing techniques such as point sensors or satellite mapping can have high associated...
The radioactivity background are among the main backgrounds (BGs) affecting low energy neutrino analysis in Super-Kamiokande (SK), like the solar neutrino analysis. Among them, the main contribution is coming from Rn-222, which is spread in the detector's water due to the water source and to the PMTs emanations. However, up to now, its exact distribution in the detector was not known. Using...
The CALorimetric Electron Telescope (CALET) was launched in August 2015 and installed on the International Space Station (ISS) Japanese Experiment Module Exposed Facility. Alongside the primary science targets of GeV—TeV energy cosmic-ray electrons and cosmic-ray hadrons up to PeV energies, CALET is sensitive to gamma rays from 1 GeV up to 1+ TeV, limited by statistics. Access to energies...
The wealth of smartphone data collected by the Cosmic Ray Extremely Distributed Observatory (CREDO) greatly surpasses the capabilities of manual analysis. So, efficient means of rejecting the non-cosmic-ray noise and identification of signals attributable to extensive air showers are necessary. To address these problems we discuss a Convolutional Neural Network-based method of artefact...
We explore applications of machine learning in particle astrophysics. A supervised machine learning algorithm is applied to the visual representations of the energy deposits in two orthogonal views of the calorimeter of ISS-CREAM. Convolutional Neural Networks (CNNs) backed by Tensorflow are used to calibrate the sampled energy of the calorimeter and reconstruct the total primary energy of...
DAMPE is a space-borne experiment for the measurement of the cosmic- ray fluxes at energies up to around 100 TeV per nucleon. At energies above several tens of TeV, the electronics of DAMPE calorimeter would saturate, leaving certain bars with no energy recorded. It is also observed that at high energies the tracker and the scintillator detector that serve for the charge identification become...
The origin of Galactic Cosmic rays (GCRs), whose spectrum extends to PeV energies, is one of the longest-standing problems in astroparticle physics. One of the main sources of GCRs are regarded to be Supernova remnants (SNRs). While SNRs are known to accelerate protons, so far there is no evidence that SNRs can accelerate CRs to PeV energies. Providing that ~10% of the parent Cosmic ray energy...
Gamma-ray bursts (GRBs), the most luminous explosions in the universe, have at least two types known. One of them, short GRBs, have been thought to originate from binary neutron star (BNS) mergers. The discovery of GW170817 together with a GRB was the first and only direct proof of the hypothesis, and thus the properties of the short GRBs are poorly known yet. Aiming to clarify the underlying...
Cosmic rays are thought to be efficiently produced in collisionless shocks in high-energy astrophysical sources, where cosmic rays are diffusively scattered by magnetic fluctuations. The magnetic field near the shock decides the maximum energy of cosmic rays accelerated in the shock and the emission by the accelerated particles. However, the magnetic field strength and structure around the...
In a collaboration between astroparticle physicists, animation artists from the award-winning Science Communication Lab, and musician Carsten Nicolai (a.k.a. Alva Noto), two cosmic particle accelerators have been brought to life: the massive binary star Eta Carinae, and the exploding star, which resulted in the gamma-ray burst GRB190829A. For Eta Carinae, the computer-generated images are...
One often needs to decide how far to introduce students to topics from the abstract scientific and mathematical perspective. It goes hand in hand with Stoffdidaktik (Dilling et al., 2020).
Referring to this question we developed and tested educational materials on Particle Physics and Cosmology for students of grade 9 to 12 at secondary and upper secondary level, and for gifted students in...
In this paper we infer the mass composition of the ultra high energy cosmic rays (UHECRs) from measurements of $X_{\rm max}$ distributions recorded at the Pierre Auger (2014) and Telescope Array (TA) (2016) Observatories, by fitting them with all possible combinations of Monte Carlo (MC) templates from a large set of primary species (p, He, C, N, O, Ne, Si and Fe) as predicted by EPOS-LHC,...
The mass composition of ultra-high-energy cosmic rays can be analyzed by employing deep neural networks. We present an improved version of such analysis for Telescope Array's surface detectors data. Our neural network was trained on a large Monte-Carlo dataset simulating the expected experimental data distribution, and then was applied to the actual experimental data. Systematic and model...
The interplanetary magnetic field (IMF) between the Sun and the Earth induces the displacement of the cosmic-ray Sun shadow from the optical position. Previously, the average IMF has been measured by the ARGO-YBJ and the Tibet-ASgamma experiments through several years of data. With the improvement of the sensitivity, the first pool of WCDA in LHAASO, which has obtained nearly one year's...
The large area muon telescope of GRAPES-3 has been operating continuously for more than two decades with a DAQ which has several limitations. At present, this DAQ is in the process of being upgraded with a FPGA based system. The new DAQ system is designed to be triggerless and capable of recording every hit from the 3712 proportional counters along with a time-stamp (10 ns accuracy) which has...
The Moon prevents cosmic rays along its direction from reaching Earth, giving rise to a deficit in the flux of cosmic rays. The observed deficit can be used for obtaining the absolute calibration of the angular resolution and to verify the pointing accuracy of the array. GRAPES-3 is an extensive air shower experiment located at Ooty, India consisting of a dense array of scintillator detectors....
Using a setup for testing a prototype for a satellite-borne cosmic-ray ion detector, we have operated a stack of scintillator and silicon detectors on top of the Princess Sirindhorn Neutron Monitor (PSNM), an 18-counter NM64 detector at 2560-m altitude at Doi Inthanon, Thailand. Monte Carlo simulations have indicated that about 15% of the neutron counts by PSNM are due to interactions (mostly...
The High-Energy Particle Detector (HEPD-01) is one of the two particle detectors installed on board the China Seismo-Electromagnetic Satellite (CSES-01). The instrument consists of different subdetectors, including two planes of double-sided silicon microstrip sensors, a calorimeter constituted by 16 plastic scintillators and a layer of LYSO crystals, and a scintillator veto system surrounding...
The JEM-EUSO Program aims at the realization of the ultra-high energy cosmic ray (UHECR) observation in the satellite orbit by the air fluorescence technique. The Mini-EUSO mission is the first space-based pathfinder mission of the program that has been conducted on the International Space Station since 2019. The Mini-EUSO detector consists of a 25 cm refractive optics that focuses the UV...
The observed correlation between the far-infrared and radio luminosities of galaxies illustrates the close connection between star formation and cosmic-ray production. Intriguingly, recent LOFAR observations find a peculiar radio excess in galaxies with low star-formation rates and high stellar masses. We show that recycled/millisecond pulsars (MSPs) can dominate the nonthermal emission in...
Macroscopic dark matter (or macro) provides a broad class of alternative
candidates to particle dark matter. These candidates would transfer
energy primarily through elastic scattering, and this linear energy
deposition would produce observable signals if a macro were to traverse
the atmosphere. We study the fluorescence emission produced by a macro
passing through the atmosphere. We...
The remnant of SN 1987A is the best-studied object of its kind. The rich data-set of its thermal and non-thermal emission across the electromagnetic spectrum poses a unique testbed for the elaboration of particle-acceleration theory.
We use 2D simulations of the progenitor's wind to obtain hydro-profiles for the medium around the supernova explosion. Various cones along prominent features...
Arrival directions of galactic cosmic rays observed at the Earth are not completely uniform; at TeV energies there are small yet significant anisotropic features with amplitudes of roughly 0.1% such as large-scale deficit and excess regions called “Loss-Cone” and “Tail-In”, respectively. The origin of the anisotropy has not been known yet, although the anisotropy is considered to reflect how...
We fit the ultrahigh-energy cosmic-ray (UHECR, $E>0.1$ EeV) spectrum and composition data from the Pierre Auger Observatory at energies $E>5\cdot10^{18}$ eV, i.e., beyond the ankle using two populations of astrophysical sources. One population, accelerating dominantly protons ($^1$H), extends up to the highest observed energies with maximum energy close to the GZK cutoff and injection spectral...
The H.E.S.S. Collaboration has firmly detected gamma-ray emission from HESS J1846-029, which is spatially coincident with Kes 75 (G29.7-0.3), one of the youngest composite supernova remnants in the Galaxy. This remnant contains the nebula of PSR J1846-0258, a glitching young pulsar with a particularly high spin-down luminosity that has manifested magnetar-like bursts in 2006. However, H.E.S.S....
A flare in 2017 from TXS0506+056 has 3.5$\sigma$ spatial as well as temporal correlation with IceCube-170922A neutrino event above energy 290 TeV. The multi-wavelength modeling of the source is one of the viable way to figure out its energetics to produce neutrino. Several models on considering lepto -hardronic channels to produce the gamma rays and neutrino from this blazar has already been...
Gamma-ray emission in active galaxies is expected to originate in a close priximity of the supermassive black hole surrounded by a reach cluster of luminous stars. We consider the effects of luminous stars (early type of red supergiant, separate or in binary systems) crossing accidentally the gamma-ray beam close to the observer's line of sight. We show that soft radiation of massive stars can...
*The observed weakening of the global magnetic field of the Sun, which began at the end of the 22nd cycle of solar activity (SA) raise the question of the response of this phenomenon in cosmic rays (CR) propagating in the heliosphere. Weak long-term modulation in the 23rd and 24th cycles of SA is the result of the trend of the solar field in cycles with different signs of the total magnetic...
The first Large Size Telescope (LST-1) proposed for the forthcoming Cherenkov Telescope Array (CTA) has recently started to operate in La Palma. The large structure of LST-1 - with a 23 m mirror dish diameter - imposes a strict control of its deformations that could affect the pointing accuracy and its overall performance. According to CTA specifications that are conceived to resolve e.g. the...
Studies of radio galaxies at TeV energies are of particular interest because their jets are misaligned with respect to our sightline. This provides us with a unique opportunity for studying the structure of their jets, the radiative processes, and the acceleration mechanisms involved in them. Some radio galaxies have presented variability in their emission, like the giant radio galaxy M87,...
The upcoming Cherenkov Telescope Array (CTA) ground-based gamma-ray observatory will open up our view of the very high energy Universe, offering an improvement in sensitivity of an order of magnitude over previous experiments. NectarCAM is one of the proposed cameras for the Medium-Sized Telescopes (MST) which have been designed to cover the core energy range of CTA, from 100 GeV to 10 TeV....
The Pierre Auger Observatory, located near Malargüe, Argentina, is the world's largest cosmic-ray detector. It comprises a $3000\:\mathrm{km}^{2}$ surface detector and 27 fluorescence telescopes, which measure the lateral and longitudinal distributions of the many millions of the air-shower particles produced in the interaction of a cosmic ray in the Earth's atmosphere. The determination of...
A project of the OLVE-HERO space detector is proposed for CR measurement in the range 1012-1016 eV and will include a large ionization 3D calorimeter with a high granularity and geometric factor of ~16 m2٠sr. The 3D structure of the calorimeter will allow registering CR particles coming from different directions. As the main NUCLEON-HERO detector is expected an image calorimeter of a boron...
The detection of cosmic neutrinos raised many new questions in astroparticle physics, the most important of which is the identification of the neutrino emitters. After more than a decade of IceCube operations, the most promising neutrino astrophysical association remains the very-high-energy (VHE, >100 GeV) blazar TXS 0506+056.
Recently, on November 14, 2020 the IceCube observatory reported...
The emission of the so-called extreme blazars challenges the particle acceleration models. The hardness of its spectrum, $<2$, demands extreme parameters using the standard one-zone SSC model in the high energy band. Some authors use both two-zone or hadronic/leptohadronic models to relax these extreme values. In this work, we present a leptohadronic multi-zone model to explain the broadband...
The origin of magnetic fields in the universe is an open problem. Seed magnetic fields possibly produced in early times may have survived up to the present day close to their original form, providing an untapped window to the primeval universe. The recent observations of high-energy neutrinos from the blazar TXS 0506+056 in association with an electromagnetic counterpart in a broad range of...
In this work, we report multi-band flux variability and correlations of the nearby (z=0.031) blazar Markarian 421 (Mrk421) using multi-wavelength (MWL) data from November 2014 until June 2016. In this period, Mrk421 exhibited historically low activity in X-rays and very-high-energy gamma rays (VHE; E>0.1 TeV). During this period, an additional spectral component was observed by Swift-BAT. The...
Muography scans large-size objects, natural or anthropic, by detecting atmospheric muon flux after crossing these buildings. Muography suffers an overwhelming background noise because of the weakness of the emerging muon flux from scanned objects. The background noise sources are scattered muons, electromagnetic particles of Extensive Air Showers (EAS), backward particles, and particles...
The presence of muons in air-showers initiated by cosmic ray protons and nuclei is well established as a powerful tool to separate such showers from those initiated by gamma-rays. However, so far this approach has been exploited only for ground level particle detecting arrays. In this contribution, we explore the feasibility of using Cherenkov light from muons as a background rejection tool...
The General Antiparticle Spectrometer (GAPS) is a balloon-borne detector, whose first flight is scheduled in the austral summer 2022,and is designed to measure low energy (<0.25 GeV/n) cosmic antinuclei. A particular focus is on antideuterons, which are predicted to have an ultra-low astrophysical background as compared to signals from dark matter annihilation or decay in the Galactic halo....
The first high-probability association of an extragalactic neutrino to the blazar TXS 0506+056 in 2017 identified such active galaxies as potential high-energy neutrino emitters.Two distinct episodes of neutrino emission were detected within 3 years, indicating a possible periodicity. Such periodic behavior is explainable by a supermassive binary black hole system close to its merger as a...
The determination of neutrino mass ordering (NMO) is one of the prime goals of several neutrino experiments. KM3NeT/ORCA and JUNO are two next-generation neutrino oscillation experiments both aiming at addressing this question. ORCA can determine the NMO by probing Earth matter effects on the oscillation of atmospheric neutrinos in the GeV energy range. JUNO, on the other hand, is sensitive to...
Theoretical predictions of the prompt atmospheric neutrino flux have large uncertainties associated with charm hadron production, by far the dominant source of prompt neutrinos in the atmosphere. The flux of cosmic rays, with its steeply falling energy spectrum, weights the forward production of charm in the evaluation of the atmospheric neutrino flux at high energies. The current LHCb...
Measurements of cosmic particle fluxes are key to indirect dark matter detection and to modeling galactic transport of cosmic rays, but all direct measurements have been made within or near our solar system, i.e. $\sim$8 kpc from the center of the Milky Way. In this work, we constrain MeV to GeV scale electron and proton populations within the central 100 pc of the Galaxy on the basis of X-ray...
The cosmic-ray fluxes of electrons and positrons ($e^{\pm}$) are measured with high precision by the space-borne particle spectrometers AMS-02. To infer a precise interpretation of the dominant production process for $e^{\pm}$ in our Galaxy, it is necessary to have a correct description of the secondary component, produced by the interaction of cosmic-ray proton and helium with the...
NASA’s Parker Solar Probe (PSP) mission’s first eight orbits include perihelia as close as ~11 million km (~16 solar radii), much closer to the Sun than any prior human-made object. Onboard PSP, the Integrated Science Investigation of the Sun (ISʘIS) instrument suite makes groundbreaking measurements of solar energetic particles (SEPs). Here we discuss the near-Sun energetic particle radiation...
Magnetic monopoles are hypothetical particles that carry magnetic charge. Depending on their velocity, different light production mechanisms exist to facilitate detection. In this work, a previously unused light production mechanism, luminescence of ice, is introduced. This light production mechanism is nearly independent of the velocity of the incident magnetic monopole and becomes the only...
The observed variablity of the cosmic-ray intensity in the interplanetary space is driven by the evolution of the Sun's magnetic activity over its 11-year quasiperiodical cycle. Investigating the relationship between solar activity indices and cosmic-ray intensity measurements is then essential for understanding the fundamental processes of particle transport in the heliosphere. In this work,...
A new experiment collects data at a depth of 210 m.w.e. in the Callio Lab [1] at the Pyhasalmi mine [2] in Finland. The setup, called NEMESIS (New Emma MEasurement with neutronS In cosmic Showers), incorporates infrastructure from the EMMA experiment [3] with neutron and large-area plastic scintillator detectors of the MAZE system [4]. The experiment's primary aim is to combine muon tracking...
The H.E.S.S. experiment has entered a new phase with an advanced camera, improved hardware, optimized operational procedures and enhanced open source analysis tools. This results in a significant gain in performance, observing time and sensitivity with corresponding benefits for quantity and quality of observational results in time-domain and time-integrated studies.
Beyond individual...
ANTARES is a Cherenkov underwater neutrino telescope operating in the Mediterranean Sea since 2008 in its full configuration. Even though optimised for the search of cosmic neutrinos, this telescope is also sensitive to nuclearites of strange matter.
We discuss here the possible detection of non-relativistic down-going nuclearites with the ANTARES telescope and present the first results of...
The observation of cosmic ray Helium isotopes (Helium-3 and Helium-4) at the Earth had been done with the PAMELA and AMS-02 space detectors, from July 2006 to December 2007 and May 2011 to November 2017, respectively. These available observations span time frames that include the solar magnetic field reversal epoch. In this work, a comprehensive, three-dimensional numerical modulation model...
Starting from the first unequivocal detection of very high energy (VHE) emission from the luminous gamma-ray burst (GRB) GRB 190114C by the MAGIC telescopes, four detections of VHE emission from GRBs by ground-based telescopes were reported as of today. Such new energetic components were missing for a long time and these observations have become a new probe to explore GRB physics. In order to...
We report a precise measurement of the sub-GeV atmospheric gamma-ray spectrum at balloon altitude on GRAINE 2018 experiment, and comparisons with the predictions calculated by the latest HKKM, which is widely known as a model for atmospheric neutrino flux calculation.
Understanding the interactions between cosmic rays and atmospheric nuclei is important for accurate atmospheric neutrino flux...
The ANTARES neutrino telescope is operating in the Mediterranean Sea in its full configuration since 2008. On their journey to the Earth, cosmic rays (CRs) can be absorbed by celestial objects, like the Sun, leading to a deficit in secondary muons produced by CR interactions from the solid angle region covered by the Sun, the so-called Sun "shadow" effect. This phenomenon can be used to...
The Alpha Magnetic Spectrometer collected over 150 billion cosmic rays events during the first 8.5 years of operation aboard the International Space Station. A component of Z>2 ions with rigidities below the rigidity cutoff and located in the South Atlantic Anomaly have been measured both in the down-going and up-going direction.
Blazars are a subclass of radio-loud active galactic nuclei, where the jet is aligned close to the line of sight. Blazars emission is dominated by non-thermal processes, where Doppler boosted radiation originates from a relativistic population of charged particles within the jet. From radio to TeV energies, blazars are highly variable on timescales from minutes to over a year. There are...
DArk Matter Particle Explorer (DAMPE), a space-borne high energy cosmic ray and gamma-ray detector, has surveyed the whole sky for five years and collected more than 220,000 photons above 2 GeV since the launching on Dec. 17, 2015. The instrument response functions (IRFs) are derived and a dedicated software named DmpST is developed for the gamma-ray data analysis of DAMPE. Here we present the...
Cosmic rays are high energy particles that come from outside of the solar system. It plays an important role in the evolution of our Galaxy. Gamma rays, produced by cosmic rays , are unique probe of cosmic rays and their accelerator. As a key sub-array of the Large High Altitude Air Shower Observatory (LHAASO), KM2A is the most sensitive gamma-ray detector at ultra-high energy (UHE, >100TeV)....
On March 2019 a Space Weather Laboratory was deployed at Marambio base in the Antarctic Peninsula. The main instrument installed was a cosmic ray detector based on water Cherenkov radiation. This detector is the first permanent Antarctic node of LAGO (Latin American Giant Observatory) Collaboration and it has been working continously since its installation. LAGO Project is an extended...
Baikal Gigaton Volume Detector (Baikal-GVD) is a km$^3$-scale neutrino detector currently under construction in Lake Baikal, Russia. The detector currently consists of 2016 optical modules arranged on 56 vertical strings. Further extension of the array is planned for March 2021. The data from the partially complete array have been analyzed using a $\chi^2$-based track reconstruction algorithm....
Abstract: Mrk421 is one of the brightest blazars in the northern sky. The radiation of Mrk421 is a broadband continuum ranging from radio through X-rays to gamma-rays. In the Large High Altitude Air Shower Observatory (LHAASO), the water Cherenkov detector array(WCDA) has the advantage of low energy threshold in observation of VHE flares, and is dedicated in surveying the northern sky for...
We propose a new approach for observing UHECR by detecting charged particles in the core region of EAS using a cost-effective and compact detector with a CMOS camera image sensor. In general, the core region of EAS is excluded from the measurement due to the very high particle density at which the signal saturates. However, the results of the EAS simulation predict that the particle density in...
Cosmic rays are measured at LOFAR simultaneously with a dense array of antennas and with the LOFAR Radboud air shower Array (LORA) which consists of 20 scintillators. In this contribution we present cosmic-ray energy reconstruction using radio and particle techniques and discuss the event-by-event and absolute scale uncertainties. The energies reconstructed with each method are shown to be in...
To study the nature of particles with energies greater than 5 EeV, the database of the Yakutsk array was analyzed. The array has been operating continuously for 50 years, and during this time period, unique material has been collected on the main components of air showers: the electron-photon component, muons, Cherenkov and radio emissions. Including the arrival directions of primary cosmic...
A surface detector array samples the lateral distribution of an extensive air-shower (EAS) at the ground, i.e. the density of particles as a function of the distance from the axis of the shower. The azimuthal symmetry of this measured lateral distribution is broken for EAS with a non-zero zenith angle. The resulting asymmetry, caused by atmospheric attenuation and geometrical effects,...
Supernova remnants (SNRs) are widely believed to be the dominant accelerators of Galactic cosmic rays (CRs) with energies up to the knee. The electrons and protons can be accelerated to be the ultra-relativistic particles by the shock of SNRs via the diffusive shock acceleration (DSA) mechanism. HESS J1813-178 is one of the brightest and most compact objects detected by the HESS Galactic Plane...
The persistent attempts are undertaken to show existence and investigate the special pairs of Extensive Air Showers (EAS) that can be suspected in common origin in the near space, i.e. to observe some consequence of existence of Cosmic Ray Ensembles (CRE). The remote cosmic ray stations observing EAS events are useful for this investigation. Such stations are operating within the GELATICA net...
The conditions in the heliosphere are considered during the minimum phase of the sunspot cycle when the intensity of galactic cosmic rays (GCRs) attains its maximum at the Earth. These times of maximum GCR intensity are determined for the last five sunspot minima, including the present one. From the quantitative correlation between the heliospheric factors important to the modulation of GCRs...
The presence of non-zero helicity in intergalactic magnetic fields (IGMF) is a smoking gun for their primordial origin. Helical magnetic fields break CP invariance, what can be sued as an experimental signature. An estimator $Q$ based on the triple scalar product of the wave vectors of photons generated in electromagnetic cascade from, e.g., TeV blazars has been suggested previously. Here, we...
The Cosmic Ray Energetics And Mass instrument on the International Space Station (ISS-CREAM) aims to measure the energy spectra of cosmic ray (CR) nuclei from Z=1 to Z=26 with energies from $10^{12}$ eV to $10^{15}$ eV. The calorimeter (CAL) was designed to measure the energy of the CR particles. The ISS-CREAM on-orbit data provide evidence that the CAL may have either suffered from an...
The DArk Matter Particle Explorer (DAMPE) is a Chinese cosmic-ray direct detection experiment. It has been operating smoothly on-orbit since its successful launch at the end of 2015. Currently, its sub-detectors and the satellite are in good working order. The DAMPE payload employs a BGO Calorimeter for energy measurements, trigger and e/p identification. The calorimeter is constructed of 308...
During the ongoing Covid-19 pandemic, people all over the world were forced to think about new ways of interacting with each other and this has especially challenged academics in their outreach activities with pupils. New online formats needed to be developed, and we used this opportunity to design and implement an (not only) online Masterclass using data from the KASCADE experiment. The...
The construction of the first stage of the Pierre Auger Observatory, designed
for the research of ultra-high energy cosmic rays, began in 2001 with a
prototype system. It has been collecting data since early 2004 and was
completed in 2008. The Observatory is placed at 1400 m above sea level
near Malargüe, (Mendoza province) over a vast plain of 3000 km^2 covered by
detectors, known as the...
Abstract: A planned array of 200,000 antennas covering an area of 200,000 km$^{2}$ - the GRAND project - is proposed to detect cosmic-ray,gamma-ray, and neutrino primaries in the energy range beyond $10^{17}$eV. The GRAND array will be able to detect upward-going air showers initiated by neutrino interactions in the rocks on its mountainous site, furthermore, it may also detect very inclined...
IceCube-Gen2 is a planned extension of the IceCube Neutrino Observatory at the South Pole designed to study the high-energy neutrino sky from TeV to EeV energies with a five times better point source sensitivity than the current IceCube detector. This is achieved by deploying 120 new strings with attached optical sensors in a pattern around IceCube that features considerably larger distances...
We will show that Solar Energetic Particles (SEP), as well as energetic particles generated in magnetospheres of the Earth, Jupiter, Saturn and other planets, in interplanetary space, and in atmospheres of stars have the same nature as Galactic and Intergalactic CR: they are all runaway particles from the Maxwell-Boltzmann distribution of background plasma where they were generated. Energy of...
The Extreme Energy Events (EEE) network consists in a sparse array of telescopes based on Multigap Resistive Plate Chambers, installed in high school buildings all over the Italian territory and at CERN. Besides the many research activities concerned with extensive air shower detection, long distance correlation studies and additional physics results obtained during the last decade, the EEE...
The Cherenkov Telescope Array Observatory (CTAO) will be the first ground-based gamma-ray observatory for the exploration of the extreme Universe that will be open to all scientific communities as a resource for data from unique, high-energy astronomical observation. The CTAO will have tens of telescopes located on two array sites, covering the entire gamma-ray sky: CTA-North located at the...
Mid to large size imaging atmospheric Cherenkov telescopes for gamma-ray astrophysics in the very high energy domain have a typical threshold of (20 – 200) GeV. In this energy range sensitive observations of the Crab Nebula reveal the emission from the Crab pulsar at phases P1 and P2. Observations of MAGIC show that the P2/P1 is monotonically increasing function of energy. In tens of GeV...
Production of high-energy muons in cosmic-ray air showers, relevant for deep underground detectors, depends on the properties of the primary cosmic ray as well as the atmospheric temperature through the competition between decay and re-interaction of charged pions and kaons. We present a parameterization of muon production profiles based on simulations as a function of the primary cosmic-ray...
Cosmic rays are messengers from highly energetic events in the Universe. These rare ultra-high-energy particles can be detected efficiently and in an affordable way by large arrays of radio antennas. Linearly polarized geomagnetic emission is the dominant emission mechanism produced when charged particles in air showers get deflected in the Earth’s magnetic field. The sub-dominant Askaryan...
The current studies of cosmic rays are focused on most energetic particles entering the atmosphere and producing a single Extensive Air Shower (EAS). There are, however, models predicting that interactions of high energy particles may result in Cosmic-Ray Ensembles (CRE) created far from the Earth. They could be observed as some number of correlated air showers of relatively low energies...
The TAx4 experiment is a project to observe highest energy cosmic rays by expanding the detection area of the Telescope Array (TA) experiment with newly constructed surface detectors (SDs) and fluorescence detectors (FDs). New SDs are arranged in a square grid with 2.08 km spacing at the north east and south east of the TA SD array. We use CORSIKA simulations and implement the calibration data...
The Cherenkov Telescope Array (CTA) will be the next-generation observatory in the very-high-energy (20 GeV to 300 TeV) gamma-ray astroparticle physics field. Classically, data analysis in the field maximizes sensitivity by applying quality cuts on the data acquired. These cuts, optimized using Monte Carlo simulations, select higher quality events from the initial dataset. Subsequent steps of...
The ASTRI Mini-Array is a project led by INAF to build and operate an observatory of next-generation Imaging Atmospheric Cherenkov Telescopes for ground-based gamma-ray astronomy in the energy range between 1 TeV and 200 TeV and beyond. It will be composed by 9 small-sized (4 meter in diameter) and large field-of-view (~10 degrees) double-mirror telescopes equipped with silicon photomultiplier...
The Cherenkov Telescope Array (CTA) is the future ground-based observatory for gamma-ray astronomy at very-high energies. The atmosphere is an integral part of every Cherenkov telescope. Different atmospheric conditions, such as clouds, can reduce the fraction of Cherenkov photons produced in air showers that reach ground-based telescopes, which may affect the performance. Decreased...
Over the years the global neutron monitor network (NMN) was extensively and successfully used to study variable fluxes of Galactic cosmic rays accelerated solar ions, the latter known as energetic solar particles. Recently, the NMN has been used also for space weather purposes, specifically event alerts, and to provide crucial information necessary for the assessment of the exposure to...
Since its launch, in December 2015, the DAMPE (DArk Matter Particle Explorer) satellite is taking data smoothly. The Silicon-Tungsten Tracker (STK) of DAMPE consists of six tracking planes (6x, 6y) of single-sided silicon strip detectors mounted on seven support trays. Tungsten plates (1 mm thick) are integrated in the 2nd, 3rd and 4th tray from the top to serve as photon...
Results from different methods searching for Quasi periodic oscillations
(QPOs) in blazars will be shown, indicating no significant evidence for periodic signals beyond the noise level. Blazars are a subclass of active galactic nuclei (AGN), and are highly variable objects. QPOs, which might originate from a binary black hole located at the AGN core, have been found in some blazar light...
Blazars are potential candidates of cosmic-ray acceleration up to ultrahigh energies ($E > 10^{18}$ eV). For an efficient cosmic-ray injection from blazars, $p\gamma$ collisions with the extragalactic background light (EBL) and cosmic microwave background (CMB) can produce neutrino spectrum with peaks near PeV and EeV energies, respectively. We analyze the contribution of these neutrinos to...
The Large Size Telescope (LST) prototype of the future Cherenkov Telescope Array (CTA) is located at the Northern site of CTA, on the Canary Island of La Palma. It is designed to provide optimal performance in the lowest part of the energy range covered by CTA, observing gamma rays down to energies of tens of GeV. The LST prototype started performing astronomical observations in November 2019...
The 2nd TAIGA imaging air Cherenkov telescope (IACT) has successfully been put into operation in the Tunka Valley in fall 2020. Currently two more telescopes are under construction and completion. The ability to use the telescopes in the so-called stereo mode of image analysis by taking into account the unusually large distance between them (from 320 m to 500 m), well exceeding the...
High-energy astrophysical neutrinos, discovered by IceCube, are now regularly observed, albeit at a low rate due to their low flux. As a result, open questions about high-energy neutrino astrophysics and particle physics remain limited by statistics at best, or unanswered at worst. Fortunately, this situation will improve soon: in the next few years, a host of new neutrino telescopes,...
The Icecube neutrino observatory is a cubic-kilometer particle detector located at the South Pole. A system of public real-time alerts on neutrino candidate events likely to be of astrophysical origin has been operating since 2016. On November 14th 2020, a track-like event with a high probability of being of astrophysical origin (IC-201114A) was reported. 4FGL J0658.6+0636, a source of the...
The detailed measurement of the daily electron fluxes from May 20, 2011 to October 29, 2019 with the Alpha Magnetic Spectrometer on the International Space Station, is presented. Time variation of the fluxes on different time scales associated with the solar activity over half solar cycle 24 is shown. The measured effect of charge sign dependent effects on particles with the same mass is discussed.
The precision measurement of the daily helium fluxes from May 20, 2011 to October 29, 2019 with the Alpha Magnetic Spectrometer on the International Space Station, is presented. The period of observation covers half solar cycle 24 from the ascending phase through its maximum going toward its minimum. Time variation of the fluxes on different time scales associated to the solar activity, are...
The detailed measurement of the positron fluxes from May 20, 2011 to October 29, 2019 with the Alpha Magnetic Spectrometer on the International Space Station, is presented. Time variation of the fluxes on different time scales associated with the solar activity over half solar cycle 24 is shown. The measured effect of charge sign dependent effects on particles with the same mass is discussed.
The spectrum of ultra high energy (UHE) cosmic rays as measured by the Pierre Auger Observatory indicates a strong flux suppression above 50 EeV. The origin of this suppression is still unclear. One possible explanation is the Greisen-Zatsepin-Kuzmin (GZK) process, in which UHE protons interact with the cosmic microwave background. Indirect evidence for the GZK-process could be provided by the...
The evidence for dark matter particles, $\chi$, is compelling based on Galactic to cosmological scale observations. Thus far, the promising weakly interacting massive particle scenario have eluded detection, motivating alternative models of dark matter. We consider scenarios involving superheavy dark matter (SHDM) that potentially can decay or annihilate to neutrinos and antineutrinos.
In...
Among theoretical approaches in unveiling the physics of ultra-high-energy cosmic rays (UHECR) one can distinguish the models assuming interactions of exotic super-heavy matter (including extra dimensions, Lorentz invariance violation, cosmic strings, dark matter particles or particles beyond the standard model etc.) and acceleration scenarios describing processes, in which the particles are...
Despite notable improvements made in the last decades, the characterization of the near-Earth proton radiation environment is incomplete, with major uncertainties affecting the description of high-energy particles (>50 MeV) in the South Atlantic Anomaly (SAA) region.
The High-Energy Particle Detector (HEPD) on board the China Seismo-Electromagnetic Satellite (CSES-01), launched on February...
The Schwarzschild-Couder Telescope (SCT) is a candidate for medium-sized telescopes of the Cherenkov Telescope Array (CTA). CTA will enable improvements in multi-wavelength and multi-messenger observations due to higher angular resolution and increased sensitivity, capable of detecting Crab-like gamma-ray point sources nearly 100 times faster than current arrays. A prototype SCT (pSCT) has...
Two high-altitude polar neutron monitors DOMC and DOMB (Dome C, Concordia station, Antarctic plateau, 3233 m a.s.l.) received a major electronics upgrade in 2019. While a typical standard neutron monitor data acquisition (DAQ) system only registers the number of pulses from a cosmic-ray particle detector, the new system digitizes all pulses with 2 MHz sampling rate and stores this information...
Long-term measurements from the global neutron monitor (NM) network allow to study galactic cosmic ray (GCR) variations for the last seven decades. However, the network offers data of quite different quality from the many sources. Historically, NM data is distributed through different data repositories, which include the Neutron Monitor Database (NMDB), World Data Center for Cosmic Rays...
The source, propagation and acceleration mechanism of Ultra High Energy Cosmic Rays (UHECRs) has been investigated since the first discovery of UHECRs to solve the mystery about the extremely-high energy universe. The Telescope Array times 4 (TAx4) experiment, which currently consists of 257 Surface Detectors (SDs) and 2 Fluorescence Detector (FD) stations, had been built in Utah, USA in 2019....
The General Antiparticle Spectrometer (GAPS) experiment is designed to detect low-energy (< 0.25 GeV/n) cosmic-ray antinuclei as indirect signatures of dark matter. Several beyond-the-standard-model scenarios predict a large antideuteron flux due to dark matter decay or annihilation compared to the astrophysical background. The GAPS experiment will perform such measurements using long-duration...
One possible way to determine the mass of cosmic rays is to study the longitudinal development of the air shower. The depth of the muon production maximum is sensitive to the nature of the primary particles and also helps to provide insight on whether new physics phenomena take place. The muon detectors of KM2A in Large High Attitude Air Shower Observation (LHAASO) record hitting time and...
The CALorimetric Electron Telescope (CALET) is a high-energy astroparticle physics experiment installed on the International Space Station, and taking data since October 2015. While designed for studying the origin and the propagation of galactic cosmic rays, CALET is also able to provide a continuous monitoring of space-weather phenomena affecting the near-Earth environment, including solar...
We have developed a portable “Changvan” neutron monitor with three counters for latitude surveys to investigate cosmic ray spectral variations. This uses the NM64 design except the middle counter lacks the lead producer, so we call this a “semi-leaded” neutron monitor. The Changvan was operated on two voyages on the Chinese icebreaker Xuelong between China and Antarctica during 2019 and...
Heavier-than-proton nuclei are responsible for up to 50% of neutron monitor (NM) response depending on the solar modulation and geomagnetic rigidity cutoff for given NM. Therefore, careful consideration of these species is important for careful analysis of NM data, including the reconstruction of the solar modulation potential using NM network data. Recently, the AMS-02 experiment allowed us...
The wide-angle Air-Cerenkov array HiSCORE is a major component of the TAIGA facility in the Tunka valley, built for Gamma Astronomy and Cosmic Ray research. HiSCORE will contain 120 stations distributed over a 1km2 area.
Here, we report a multi-year detection of light flashes in HiSCORE from the LIDAR on-board the Sun-synchronous CALIPSO satellite, obtained from 2015-2021. The 100mJ laser...
In October 2019, the central 28m telescope of the H.E.S.S. experiment has been upgraded with a new camera. The camera is based on the FlashCam design which has been developed in view of a possible future implementation in the medium-sized telescopes of the Cherenkov Telescope Array (CTA). We report here on the results of the science verification program that has been performed after...
The presence of dark matter (DM) is suggested by a wealth of astrophysical and cosmological measurements. However, its underlying nature is yet unknown. Among the most promising candidates are weakly interacting massive particles (WIMPs): particles with mass and coupling strength at the electroweak scale and thermally-produced in the early universe have a present relic density consistent with...
The nature of Dark Matter remains one of the most important unresolved questions of fundamental physics. Many models, including the Weakly Interacting Massive Particles (WIMPs), assume Dark Matter to be a particle and predict a weak coupling with Standard Model matter. If Dark Matter particles can scatter off nuclei in the vicinity of a massive object, such as a star or a planet, they may lose...
The GRAPES-3 is a high-altitude, near-equator extensive air shower array at Ooty, India which is designed to observe cosmic and gamma rays in TeV-PeV energy range. It consists of a dense array of 400 scintillator detectors operating in conjunction with a 560 $m^2$ area muon telescope. Due to recent improvements in the measurements of shower arrival time and size and age dependent corrections...
DArk Matter Particle Explorer (DAMPE) is a high energy cosmic-ray and gamma-ray observatory with an excellent energy resolution, and therefore has an advantage in searching for gamma-ray line structures. Based on the 5-yr DAMPE observation, we construct a dedicated data set for line search which balances the energy resolution and acceptance. We also make use of the photons converted in the BGO...
The importance of search for neutrino generation during solar flare has been discussed for last 50 years while the detection has not been succeeded yet. Since neutrinos are not affected by interplanetary magnetic field, neutrinos associated with solar flares (solar flare neutrino) provides us information about a particle acceleration mechanism during solar flare. According to theoretical...
The IceCube neutrino observatory--installed in the Antarctic ice--is the largest neutrino telescope to date. It consists of 5,160 photomultiplier-tubes spread among 86 vertical strings making a total detector volume of more than a cubic kilometer. IceCube detects neutrinos via Cherenkov light emitted by charged relativistic particles produced when a neutrino interacts in or near the detector....
Galaxy clusters' dynamics constitute a major piece of evidence for the existence of dark matter in astrophysical structures. The decay or annihilation of dark matter particles is hypothesized to produce a steady flux of very-high-energy gamma rays correlated with the direction of a cluster of galaxies. The Virgo cluster, being only ~16 Mpc away and spanning several degrees across the sky is an...
PSR J0218+4232 is a millisecond pulsar (MSP) with high magnetic field strength at the light-cylinder radius ($B_{LC}$ ∼ 3.2 × $10^{5}$ G), making it one of the best candidates for VHE gamma-ray emission. It was one of the first MSPs detected by Fermi-LAT at high energy. The source is possibly an aligned rotator with large unpulsed component(∼50%) in radio and X-rays.
For this study, we have...
The IceCube Neutrino Observatory is a cubic kilometer-sized detector designed to detect neutrinos of astrophysical origin. However, muons created by cosmic rays interacting in the atmosphere pose a significant background for these astrophysical neutrinos particularly in the southern equatorial sky. Correctly identifying neutrino events that start in the detector allows us to reduce the...
IceCube has discovered a flux of astrophysical neutrinos, and more recently has used muon-neutrino datasets to present evidence for one source; a flaring blazar known as TXS 0506+056. However, the sources responsible for the majority of the astrophysical neutrino flux remain elusive. Opening up new channels for detection can improve sensitivity and increase the chance of a discovery. In this...
Gamma-ray bursts (GRBs) are among the most powerful events observed in our universe and have long been considered as possible sources of ultra-high-energy cosmic rays, which makes them promising neutrino source candidates. Previous IceCube searches for neutrino correlations with GRBs focused on the prompt (main emission) phase of the GRB and found no significant correlation between neutrino...
The High Altitude Water Cherenkov (HAWC) Observatory surveys 2/3 of the gamma-ray sky each day for gamma rays from 300 GeV to over 100 TeV. Using recently improved energy reconstruction, HAWC has detected several Galactic sources with emission above 100 TeV. We extend this analysis to search for >100 TeV emission in the vicinity of Mrk 501. High-energy emission from Mrk 501 could, for example,...
At low-energies, cosmic antideuterons and antihelium provide an ultra-low background signature of dark matter annihilation, decay, and other beyond the Standard Model theories. The General Antiparticle Spectrometer (GAPS) is an Antarctic balloon experiment designed to search for low-energy (0.1-0.3 GeV/n) antinuclei and is planned to launch in the austral summer of 2022. While optimized for an...
While there is evidence for the existence of dark matter, its properties have yet to be discovered. Simultaneously, the nature of high-energy astrophysical neutrinos detected by IceCube remains unresolved. If dark matter and neutrinos are coupled to each other, they may exhibit a non-zero elastic scattering cross section. Such an interaction between an isotropic extragalactic neutrino flux and...
Around one third of the point-like sources in the Fermi-LAT catalogs remain as unidentified sources (UniDs) today. Indeed, these unIDs lack a clear, univocal association with a known astrophysical source identified at other wavelengths, or to a well-known source type emitting only in gamma rays (such as certain pulsars). If the dark matter (DM) is composed of weakly interacting massive...
The existence of fractionally charged particles (FCP) in present is some extensions to the Standard Model of particle physics, and their detection would be a significant breakthrough. Most of the previous cosmic-rays (CRs) studies are mainly focused on the secondary CRs from the extensive air shower, but there is rarely on-orbit study to search FCP from primary CRs. The DArk Matter Particle...
Magnetars are neutron stars with very strong magnetic fields on the order of $10^{13}$ to $10^{15}$ G. Young magnetars with oppositely-oriented magnetic fields and spin moments may emit high-energy (HE) neutrinos from their polar caps as they may be able to accelerate cosmic rays to above the photomeson threshold (Zhang, et. al 2003). Giant flares of soft gamma-ray repeaters (a subclass of...
Particles with fractional electric charge can be copiously produced in cosmic rays showers, propagating through the atmosphere and penetrating the earth until they reach different kinds of underground experiments. We will revisit their atmospheric production and provide novel sensitivity estimates for both, Cherenkov and Scintillator-based experiments.
Recent observations of GeV gamma-rays from novae have led to a paradigm shift in the understanding of these objects. While it is now believed that shocks contribute significantly to the energy budget of novae, it is still unknown if the emission is hadronic or leptonic in origin. Neutrinos could hold the key to definitively differentiating between these two scenarios, though the energies of...
X-ray binaries are long-standing candidates for the source of Galactic cosmic rays and neutrinos. The compact object in a binary system can be the site for cosmic-ray acceleration, while high-energy neutrinos can be produced by the interactions of cosmic rays in the jet of the compact object, the stellar wind, or the atmosphere of the companion star. We report a time-dependent study of...
Competition between decay and re-interaction of charged pions and kaons depends on the temperature/density profile of the upper atmosphere. The amplitude and phase of the variations depend on the minimum muon energy required to reach the detector and on muon multiplicity in the detector. Here we compare different methods for characterizing the muon production profile and the corresponding...
The IceCube Neutrino Observatory is a detector array at the South Pole with the central aim of studying astrophysical neutrinos. However, the majority of the detected neutrinos originates from cosmic ray interactions in the atmosphere. The rate of these atmospheric neutrinos shows a seasonal variation indicating that the rate changes with the temperature in the stratosphere. These seasonal...
The identification of cosmic objects emitting high energy neutrinos could provide new insights about the Universe and its active sources. The existence of these cosmic neutrinos has been proven by the IceCube collaboration, but the big question of which sources these neutrinos originate from, remains unanswered. The KM3NeT detector for Astroparticle Research with Cosmics in the Abyss (ARCA),...
Ground Level Enhancement (GLE) events of solar cosmic ray refer to the sudden, sharp and short-lived enhancement of ground level energetic particles generated from solar flare. The study of GLE events has been playing an important role in the study of solar activity and basic physics of cosmic rays. The Large High Altitude Air Shower Observatory (LHAASO), a multi-component instrument, is...
A primordial magnetic field with the strength in the 1-10 pG range can resolve the tension between different measurements of the Hubble constant and provide an explanation for the excess opacity in the 21 cm line at redshift 15<z<20, if it is present during the recombination and reionization epochs. This field can also survive in the voids of the large-scale Structure in the present day...
The ICARUS collaboration employed the 760-ton T600 detector in a successful three-year physics run at the underground LNGS laboratories studying neutrino oscillations with the CNGS neutrino beam from CERN, and searching for atmospheric neutrino interactions. ICARUS performed a sensitive search for LSND-like anomalous $\nu_e$ appearance in the CNGS beam, which contributed to the constraints on...
In this work, we present a detailed description of the simulation development and validation of the underground detector signal for the Auger Muons and Infill for the Ground Array (AMIGA), a low-energy enhancement at the Pierre Auger Observatory. To this aim, the detection system was thoroughly characterized in the laboratory. It consists of plastic-scintillator strips with optical fibers that...
Extensive Monte Carlo (MC) simulations are essential in understanding the detector’s response for high-energy particle detection experiments. We present the infrastructure and status of MC simulations of the DArk Matter Particle Explorer (DAMPE), a satellite project for the direct detection of high-energy cosmic rays and gamma rays. The DAMPE simulation tool employs two widely used softwares,...
Currently new techniques are being explored to detect astrophysical neutrinos beyond the PeV scale interacting in polar ice by means of the emitted radio waves. Due to the long attenuation length of radio waves in a medium, it can be expected that such instruments will also be sensitive to the in-air radio emission of cosmic ray air showers. Furthermore, cosmic ray air showers hitting a...
The MACE (Major Atmospheric Cherenkov Experiment) is an Imaging Atmospheric Cherenkov Telescope (IACT) located in Hanle, India. It has highest altitude of 4270 m among all the IACTs in the world. The high altitude of MACE along with its large reflector having diameter of 21 m is expected to yield wide energy coverage of ~20 GeV to ~20 TeV. We have carried out detailed Monte Carlo...
LHAASO, located at Daocheng in Sichuan province of China with an altitude up to 4410 m above the sea level, takes the function of hybrid technology to detect cosmic rays. As the major array of LHAASO, KM2A is composed of 5195 electromagnetic particle detectors (EDs) and 1188 muon detectors (MDs). In the ground-based experiments, there are two common independent data acquisition systems,...
Cosmic Ray Ensembles (CRE) are yet not observed groups of cosmic rays with a common primary interaction vertex or the same parent particle. One of the processes capable of initiating identifiable CRE is an interaction of an ultra-high energy (UHE) photon with the solar magnetic field which results in an electron pair production and the subsequent synchrotron radiation. The resultant...
Mini-EUSO is a mission of the JEM-EUSO program flying onboard the International Space Station since August 2019. Since the first data acquisition in October 2019, more than 35 sessions have been performed for a total of 52 hours of observations. The detector has been observing Earth at night-time in the UV range and detected a wide variety of transient sources all of which have been modeled...
In last few years, SiPMs have emerged as a viable alternative to PMTs used in the imaging atmospheric Cherenkov telescopes. In addition to their higher photon detection efficiency, SiPMs provide attractive features like possible increase in observation duty cycle owing to their safe operation under partial moonlight conditions. Design and development of 256 pixel based SiPM camera for a 4m...
We have noticed in many places around the world in recent years an increasing interest in small-scale extensive air shower experiments designed to satisfy young people's scientific curiosity and develop their interest in science and in physics in particular. It is difficult to think of ways and opportunities to introduce practical classes in modern high-energy physics, astrophysics, or...
The Galactic cosmic ray spectrum manifests subtle variations over the 22-year solar magnetic cycle in addition to more pronounced variations over the 11-year sunspot cycle. We conducted numerous latitude surveys by operating a neutron monitor onboard an icebreaker that traveled across a wide range of geomagnetic cutoff rigidities. Here we revisit our previous work to study spectral changes...
Fast neutrons generated by the interaction between ions and the solar atmosphere are important observation probles to clarify the ion acceleration mechanism in the Sun, but so far neutrons have been detected from only 12 X-class solar flares in the highland on the ground due to the influence of atmospheric absorption. As for observations in space, SEDA-AP at the International Space Station...
The DIMS (Dark matter and Interstellar Meteoroid Study) experiment is designed to study macroscopic dark matters such as nuclearites/strange quark matters (SQM) and interstellar meteoroids. The DIMS experiment system is under construction at the Telescope Array (TA) cosmic-ray experiment site in Utah, USA. The system consists of 4 high-sensitivity CMOS camera stations which will be installed...
In the last decade, very-high-energy gamma-ray astronomy has reached maturity: over 200 sources have been detected, both Galactic and extragalactic by ground-based experiments. At present, Active Galactic Nuclei (AGN) make up about 40% of the 200+ sources detected at very high energies with ground-based telescopes, the majority of which are blazars, i.e. their jets are closely aligned with the...
The isotropic diffuse γ-ray background (IGRB) comprises of all extragalactic diffuse emission that is not resolved into sources and is found to be approximately isotropic on large angular scales. The initial measurement of the IGRB intensity with the Fermi Large Area Telescope (LAT) was performed in 2010 using the first 10 months of sky-survey data. After improvements were made in event...
A wide range of data formats and proprietary software have traditionally been used in gamma-ray astronomy, usually developed for a single specific mission or experiment. However, in recent years there has been a shift towards making astronomical data open and accessible. Within the gamma-ray community this has translated to the creation of a common data format across different gamma-ray...
Sunspot area varies over the Sun’s disk and is to be heliospheric behavior during the descending phase of solar cycle 22 to 24. Galactic Cosmic rays encounter an outward-moving solar wind with cyclic magnetic-field fluctuation and turbulence. This causes convection and diffusion in the heliosphere. We have observed that the galactic cosmic rays recoveries are much faster than the solar...
The propagation of cosmic rays through the heliosphere is solved for more than half a century by stochastic methods based on Ito's lemma. This work presents the estimation of statistical error of solution of Foker – Plank equation by 1D forward stochastic differential equations method.
The error dependence on simulation statistics and energy is presented for different combinations of input...
Despite numerous detections of individual flares, the cause of the rapid variability observed from blazars remains uncertain. Using Bayesian blocks and the HOP algorithm, we characterize all significant flux variations in a set of light curves and determine the statistical properties of the rise and decay behavior in order to constrain the physical mechanisms driving blazar variability....
KCDC, the 'KASCADE Cosmic-ray Data Centre', is a web-based interface where initially the scientific data from the completed air-shower experiment KASCADE-Grande was made available for the astroparticle community as well as for the interested public. Over the past 7 years, we have continuously extended the data shop with various releases and increased both the number of detector components from...
The VERITAS Imaging Air Cherenkov Telescope array IACT) was augmented in 2019 with high-speed focal plane electronics to allow the use of VERITAS for Stellar Intensity Interferometry (SII) observations. Since that time, a number of improvements have been made to increase the sensitivity of VSII and increase the speed of nightly data processing. This poster will describe the use of IACT arrays...
Cosmic@Web is an online learning resource developed at DESY Zeuthen, Germany as part of the outreach activities in the framework of Netzwerk Teilchenwelt. Via Cosmic@Web, high school and university students can access data from astroparticle physics experiments and experience the workflow of scientific research in this field by pursuing their own or suggested research questions. Data from...
IceTop is the surface instrumentation of the IceCube Neutrino Observatory at the South Pole. It is designed to measure extensive air showers of cosmic rays in the primary energy range from PeV to EeV. Air showers induced by heavier primary particles develop earlier in the atmosphere and produce more muons observable at ground level than lighter cosmic rays with the same primary energy....
A small anisotropy in the arrival directions of comic rays has been consistently observed by ground detectors based on very large sample of events. The Dark Matter Particle explorer (DAMPE) has so far accumulated nearly 10 billion events above GeV with relatively high spatial and energy resolution, expected to be the space detector to observe the anisotropy of cosmic rays. We introduce in this...
Sources of astrophysical neutrinos can be potentially discovered through the detection of neutrinos in coincidence with electromagnetic or gravitational waves. Real-time alerts generated by IceCube play an important role in this search since they act as triggers for follow-up observations with instruments sensitive to other wavelengths.
Once a high-energy event is detected by the IceCube...
The measurement of thermal neutrons generated by cosmic ray extensive air showers (EAS) on the Earth’s surface provides a new method for studying the composition and energy of cosmic rays with energy in the so-called “knee” region. A new type of thermal neutron detector prototype array was installed in LHAASO, Haizishan, Daocheng, Sichuan, China. The array consists of 16 electron-neutron...
LHAASO-KM2A is a sub-array of the Large High Altitude Air Shower Observatory (LHAASO) with an area of 1.3 km2. It consists of 5195 electromagnetic detectors (EDs, 1 m2 each) and 1171 muon detectors (MDs, 36 m2 each). Horizontal Air Showers (HAS) are a fundamental tool to detect penetrating particles like neutrinos and to study hadronic interactions. HAS detected at ground are mainly...
The Compton Spectrometer and Imager (COSI) is a balloon-borne compact Compton telescope (CCT) designed to survey the gamma-ray sky in 0.2-5 MeV. COSI's wide field of view, excellent energy resolution from cross-strip high-purity germanium semiconductor detectors, and improved angular resolution make it uniquely capable to probe this under-explored energy regime and make contributions to...
One of the consequences of having a high-density calorimeter as part of an experiment is a large number of secondary shower particles generated in the calorimeter -- some of which scatter back up towards the charge measurement devices. This so-called "backscatter effect" can interfere severely with accurate charge measurement of the primary nucleus, especially at high energies, as the number...
By adding suitable amount of Rh compound (Na$_3$RhCl$_6$∙5H$_2$O) during the production of nuclear emulsion gel, it enabled to reduce the sensitivity of the nuclear emulsion films and realized the selection of heavy nuclei by using image processing system suitable for minimum ionized particles. We have carried out the beam exposure of desensitized nuclear emulsion films in October, 2019 at...
The Wide Field of View Cherenkov Telescope Array (WFCTA) is an important component of Large High Altitude Air Shower Observatory(LHAASO), which aims to measure the individual energy spectra of cosmic rays from ~30TeV to a couple of EeV. WFCTA consisting of 18 imaging air Cherenkov telescopes, each have 32 × 32 pixels, covering a field of view 16o × 16o (each pixel corresponding to 0.5o ×...
The IceCube Neutrino Observatory is a multi-component detector at the South Pole which detects high-energy particles emerging from astrophysical events. These particles provide us with insights into the fundamental properties and behaviour of their sources. Besides its principal usage and merits in neutrino astronomy, using IceCube in conjunction with its surface array, IceTop, also makes it a...
Momentum diffusion of the energetic charged particles is an important mechanism of the
transport process in astrophysics, physics of the fusion devices, and laboratory plasmas.
In the light of observations, for the investigation of energetic particle
transport through magnetized plasma, one usually assumes the
magnetic field configuration as the superposition of the background
magnetic...
EUSO-TA is a ground-based experiment, placed at Black Rock Mesa of the Telescope Array site as a part of the JEM-EUSO (Joint Experiment Missions for the Extreme Universe Space Observatory) program. The fluorescence detector with a field of view of about 11$^\circ$ x 11$^\circ$ consisting of 2304 pixels (36 Multi-Anode Photomultipliers, 64 channels each) works with 2.5-microsecond time...
The aim of this project is to study the potential effect that the changes in geoelectric and geomagnetic fields, produced by seismic activity, could have on the detection of secondary particles from extensive air showers in the atmosphere. For this purpose, simulations for flux of secondaries are performed using ARTI, a tool developed by the LAGO Collaboration that combines Magnetocosmics,...
eHWC J1825-134 is one of the brightest Galactic gamma-ray sources above 50 TeV observed by High Altitude Water Cherenkov Gamma-Ray Observatory (HAWC). Detailed morphological studies have revealed a new point-like source inside this region with a spectral energy distribution extending beyond 200 TeV without any cutoff. These very-high-energy gamma rays emission can originate from leptonic or...
The PAMELA experiment had operated almost ten years on board of the Resurs DK1 satellite. The satellite was launched on 15 June 2006 and placed in orbit with an inclination of 70° and an altitude of 350–610 km. The experiment continuously measured electron and positron fluxes of galactic cosmic rays in a wide energy range from 50 MeV to hundreds of GeV. The spectra of electrons and positrons...
Although at extreme energies (>50 TeV) γ-ray sources generally have large angular separations from one another as observed on Earth, at lower energies in the galactic plane this is often not the case. HAWC observes extended emission from the source eHWC J1850+001 exceeding 50 TeV, and at lower energies this region appears to consist of multiple sources of γ-ray emission. These include the 3HWC...
MATHUSLA is a proposal to build a hodoscope of large dimensions at ground level, close to the interaction point of the CMS detector at CERN, to search for displaced vertices from the decay of neutral long-lived particles (LLP) during the High Luminosity LHC runs in an environment with low background. LLPs are predicted by different models, which try to solve open problems in fundamental...
Gamma-rays and neutrinos are important probes of astrophysical sources and acceleration mechanisms of ultra-high energy cosmic rays (UHECRs). UHECRs can interact with the radiation field and the baryonic material within the source and produce neutrinos in pion decay chains. These neutrinos are subject mostly to redshift and flavour oscillation during their propagation to Earth and contain...
The space-borne PAMELA experiment was launched on the 15th June 2006 on board the Russian satellite Resurs-DK1 from the Baikonur cosmodrome. From the beginning PAMELA performed high-precision measurements of cosmic rays over a wide energy range until January 2016. Owing to its long-duration operation, PAMELA had turned out to be an optimal detecting apparatus for studies of the solar...
The Southern Wide-field Gamma-ray Observatory (SWGO) is a next-generation ground-based gamma-ray detector under development to reach a full sky coverage together with the current HAWC and LHAASO experiments in the northern hemisphere. It will complement the observation of transient and variable multi-wavelength and multi-messenger phenomena, offering moreover the possibility to access the...
In recent years, a few groups have reported detections of gamma rays in the 100 TeV region from astronomical objects in the galaxy using extensive air shower arrays.
These observations have certainly taken a new step in the research of cosmic-ray acceleration mechanisms.
Several spread TeV gamma-ray sources have been observed in the galaxy.
To study the acceleration mechanisms, it is...
High-mass microquasars (HMMQs) are powerful particle accelerators, but their mechanism of the high-energy emission is poorly understood. To date, only a handful of these particle engines have ever been observed to emit gamma-ray photons and are thus potential TeV gamma-ray emitters. In this work, we study four HMMQs, namely, LS 5039, Cyg X-1, Cyg X-3, and SS 433 using the data from the High...
The high-frequency peaked BL Lac type object (HBL) 1ES 1959+650 is one of the brightest blazars in the very-high-energy (VHE, E > 100 GeV) gamma-ray sky. HBLs have been proposed as possible neutrino emitters implying the presence of hadrons in the emission mechanisms. In 2002, AMANDA reported neutrino candidates from this source simultaneously observed with a gamma-ray flaring activity without...
The core-collapse supernova releases a tremendous number of neutrinos, which can provide insight into many research areas, including particle physics, astrophysics, nuclear physics, and cosmology. We can detect the signal through a positron produced from the inverse beta decay (IBD) interaction between the electron antineutrino and water. The Large High Altitude Air Shower Observatory Main...
The SuperTIGER (Super Trans-Iron Galactic Element Recorder) balloon-borne ultra-heavy galactic cosmic-ray (UHGCR) detector has flown twice in the stratosphere over Antarctica at altitudes up to $\sim$130,000 ft. Corrections for propagating through the last $\sim$0.5$\%$ of the atmosphere are based on those developed for the preceding TIGER instrument. Changes due to nuclear interactions are...
Several gamma-ray observations from distant blazars show a suppressed GeV band emission of the inverse Compton cascade of the blazar-induced pair beams. There are two possible justifications, the first one is the deflections of the pair beam electrons and positrons by magnetic fields in the intergalactic medium. The second one is the drain of the pair energy by plasma beam instabilities...
Using test-particle simulations we study the acceleration of suprathermal electrons at an ICME-driven quasi-perpendicular shock on 2000 Feb 11 observed by Wind spacecraft. The downstream electron distribution in several energy channels from ~0.3 to ~40 keV are obtained assuming an initial distribution based on the observed upstream electron intensities. It is shown that in each energy channel...
Black Holes (BHs) at the center of galaxies have a $10^6$ - $10^9$
solar mass and thus are called Supermassive Black hole (SMBH). When a large amount of matter accretes onto SMBH, the accreting matter shines brightly, and this phenomenon is called active galactic nuclei (AGN). Only 10$¥%$ of AGNs have a powerful radio jet, and these objects are roughly classified either radio galaxy or...
A novel ultra-high-energy cosmic rays energy and arrival direction reconstruction method for Telescope Array surface detector is presented. The analysis is based on a deep convolutional neural network using detector signal time series as the input and the network is trained on a large Monte-Carlo dataset. This method is compared in terms of statistical and systematic energy and arrival...
The TAIGA-IACTs are part of the hybrid TAIGA experimental complex, located near lake Baikal in Tunka valley, Siberia, Russia. The telescopes have segmented mirrors in Davis-Cotton design with the reflector diameter of 4.3 m and an imaging camera with PMTs in its focus to detect nanosecond flashes of Cherenkov light from EAS. The TAIGA-IACTs are operating in wobble mode. Their operation...
TAIGA-HiSCORE is a wide-aperture Air-Cherenkov array, and is a major component of the TAIGA-Observatory (Tunka Instrument for high-energy gamma-ray astronomy and cosmic ray physics), located in the Tunka valley, 50km from Lake Baikal, Russia. A main science target of TAIGA is gamma ray astronomy above ten’s of TeV, in particular the search for sources of few 100 TeV gamma rays (candidate...
The Southern Wide-field Gamma-ray Observatory (SWGO) Collaboration is in the process of designing and prototyping a wide field of view, high duty cycle complement to CTA and the existing ground-based particle detectors of the Northern Hemisphere (HAWC and LHAASO). In this contribution, we will compare the various technological options for designing the detector and present an overarching...
The “Mathematical High School” research project is an extracurricular educational path dedicated to high school students developed by the Department of Mathematics of the University of Salerno (Italy). In this context, an experimental research-laboratory in the field of astroparticle physics was presented in collaboration with the National Institute of Nuclear Physics (INFN) – Napoli Division...
The Telescope Array (TA) experiment detects air-showers induced by ultra high energy cosmic rays. The TA atmospheric Fluorescence telescopic Detector(TAFD) observes cosmic ray airshower, which is incident very far from the telescope. The observation does not take place in overcast night. However, the cloud status changes quickly and sometimes there are some isolated clouds. If the cloud is...
We present updated results of the search for the ultra-high energy photons with primary energies greater than 1 EeV. The data of the Telescope Array Surface Detector collected over 12 years are used in this work. The method is based on the machine learning classifier, which trains on both the reconstructed composition-sensitive parameters of the event and the calibrated waveform signals at...
Solar Energetic Particles (SEPs) are known to be accelerated at Coronal Mass Ejection (CME)-driven interplanetary shocks. Traditionally their propagation has been described via focussed transport approaches, limited to 1 or 2 spatial dimensions. We use 3D test particle simulations, which naturally incorporate the effect of drifts and of the Heliospheric Current Sheet (HCS), to simulate the...
In the next decade, ultra-high-energy neutrinos in the EeV-ZeV energy range will be potentially detected by next-generation neutrino telescopes. Although their primary goals are to observe cosmogenic neutrinos and to gain insight into extreme astrophysical environments, they have the great potential of indirectly probing the nature of dark matter. In this talk, we study the projected...
The Cygnus Cocoon region is a complex region containing an OB star cluster that is prominent in the TeV energy range. Located in this region is 3HWC J2031+415, a significant TeV gamma ray source whose emission is possibly associated with 2 components, the Cygnus OB2 star cluster and a pulsar wind nebula (PWN). In this work, several modelling methods are presented to best describe the emission....
Long-lasting, very bright multiwavelength flares of blazar jets are a curious phenomenon. The interaction of a large gas cloud with the jet of a blazar may serve as a reservoir of particles entrained by the jet. The size and density structure of the cloud then determine the duration and strength of the particle injection into the jet and the subsequent radiative outburst of the blazar. In this...
We will present simulations of the instrument performance of the Advanced Particle-astrophysics Telescope (APT), a mission concept of a $\gamma$-ray and cosmic-ray observatory in a sun-Earth Lagrange orbit. The key concepts of the APT detector include a multiple-layer tracker composed of scintillating fibers and an imaging calorimeter composed of thin layers of CsI:Na scintillators and...
The CALorimetric Electron Telescope (CALET), operating aboard the International Space Station since October 2015, is an experiment dedicated to high-energy astroparticle physics. The primary scientific goal of the experiment is the measurement of the electron+positron flux up to the multi-TeV region. In this poster, we will present the analysis strategy employed for this measurement. At first,...
In the Large High Altitude Air Shower Observatory (LHAASO), the main physics objective of the Water Cherenkov detector array (WCDA) is able to survey the gamma-ray sky continuously in the energy range from 100 GeV to PeV. The water Cherenkov detector array, covering an area of about 78,000 m2 area, is constituted by 3120 detector units divided into 3 separate ponds. Each unit of the first...
The ASTRI Mini-Array (MA) is an INAF project to construct and operate an experiment to study gamma-ray sources emitting up to the TeV spectral band. The ASTRI MA consists of an array of nine Imaging Atmospheric Cherenkov Telescopes that will be deployed at the Observatorio del Teide (Tenerife, Spain). These telescopes will be an evolution of the two-mirror ASTRI-Horn telescope, successfully...
The portion of the electromagnetic spectrum above a few Teraelectronvolt (TeV) is currently being investigated by means of both ground-based imaging atmospheric Cherenkov telescopes and water Cherenkov detector arrays. In a few years, an array composed of at least nine ASTRI dual-mirror, Schwarzschild-Couder telescopes will be deployed and start scientific observations at the Observatorio del...
ASTRI-Horn is an Image Atmospheric Cherenkov Telescope located at the INAF "M.C. Fracastoro" observing station (Mt. Etna, Italy) characterized by a dual-mirror optical system and a curved focal surface equipped with SiPM sensors managed by an innovative fast front-endelectronics based on the peak detector technique.
ASTRI-Horn represents the prototype of nine similar telescopes...
The Telescope Array (TA) experiment continues to observe Ultra High Energy Cosmic Rays (UHECRs) both with its original TA detectors as well as with the new TAx4 expansion detectors. These observations employ Fluorescence Detectors (FDs) to capture the air shower induced by the primary UHECRs. The FD observes fluorescence light emitted from atmospheric nitrogen molecules excited by air shower...
Blazar hadronic models have been developed in the past decades as an alternative to leptonic ones. In hadronic models the gamma-ray emission is associated with synchrotron emission by protons, and/or secondary leptons produced in proton-photon interactions. Together with photons, hadronic emission models predict the emission of neutrinos that are therefore the smoking gun for acceleration of...
Water Cherenkov detector array (WCDA), one of major parts of LHAASO project, has been partly operated since April 2019. Each detector cell of the first pool (WCDA-1) has one 8" PMT and one 1.5" PMT. 20" PMT and 3" PMT are hung in each cell of WCDA-2 and WCDA-3. In order to achieve an optimal energy reconstruction, and cosmic ray background suppression for the air showers, we develop an...
The Cherenkov Telescope Array (CTA) is a next generation ground-based very-high-energy gamma-ray observatory that will allow for observations in the >10 GeV range with unprecedented photon statistics and sensitivity. This will enable the investigation of the yet-marginally explored physics of short-time-scale transient events. CTA will thus become an invaluable instrument for the study of the...
The Cherenkov Telescope Array (CTA) will be the next generation very-high-energy gamma-ray observatory. CTA is expected to provide substantial improvement in accuracy and sensitivity with respect to existing instruments thanks to a tenfold increase in the number of telescopes and their state-of-the-art design. Detailed Monte Carlo simulations are used to further optimise the number of...
The ALTO/COMET R&D project focuses on the development of a new technique for the observation of very high-energy (VHE) gamma-rays from the ground at energies above ~200 GeV, thus covering emission from soft-spectrum sources. The ALTO/COMET proposed array under study combines 1241 particle detector units, distributed over a circular area of ~160 m in diameter and placed at a very high altitude...
The Greisen-Zatsepin-Kuz'min (GZK) horizon traditionally sets the distance limit for sources generating the UHE CR flux detected on Earth. This horizon is caused by the strong attenuation of Ultra-high-energy (UHE) cosmic rays (CRs) due to their hadronic interactions with cosmic microwave background radiation. It has been argued that the propagation distance of UHE CRs of energies $\sim...
The Crab Nebula is a steady radiation source, which has been used as a reference source in very high energy gamma-ray astronomy for calibration and verification of detectors, however the gamma-ray flares around GeV from the Crab Nebula have been observed many times by AGILE and Fermi-LAT since 2007. These observations challenge the standard models for particle acceleration in pulsar wind...
Detecting the Diffuse Supernova Neutrino Background at Super-Kamiokande requires designing state-of-the-art background removal technique to reject radioactivity induced by cosmic muon spallation, and identify atmospheric neutrino interactions. Identifying the neutron produced by the interaction of DSNB antineutrinos would allow to remove most of these backgrounds, but is particularly...
Neutrinos have played a key role in astrophysics, from the
characterization of nuclear fusion processes in the Sun to the
observation of supernova SN1987A and multiple extragalactic events. The
Super-Kamiokande experiment has played a major part in past in these
astrophysical studies by investigating low energy O(10)~MeV neutrinos
and currently exhibits the best sensitivity to the diffuse...
In the decay phase of solar energetic particle (SEP) events, particle intensities observed by widely separated spacecraft usually present comparable intensities (within a factor of 2-3) that evolve similarly in time. The phenomenon of SEP events is called reservoir, which could be observed frequently in intensive gradual SEP events. In this work, we examine the effects of magnetic boundary on...
Hadrons are the “skeleton” of extensive air shower (EAS). They possess favorable information concerning the cosmic ray components and energy. The electron-neutron detector (EN-detector) can detect both electrons and thermal neutrons generated by EAS hadrons in surrounding matter. The electron-neutron detector array (ENDA) was proposed to add into the LHAASO project to improve its capability of...
The Latin American Giant Observatory (LAGO) is a distributed cosmic ray observatory at a regional scale in Latin America, by deploying a large network of Water Cherenkov detectors (WCD) and other astroparticle detectors in a wide range of latitudes from Antarctica to México, and altitudes from sea level to more than 5500 m a.s.l.
Detectors telemetry, atmospherics conditions and flux of...
The TurLab facility is a laboratory, equipped with a 5 m diameter and 1 m depth rotating tank, located in the fourth basement level of the Physics Department of the University of Turin.
In the past years, we have used the facility to perform experiments related to the observations of Extreme Energy Cosmic Rays (EECRs) from space using the fluorescence technique for JEM-EUSO missions with the...
The Cherenkov Telescope Array (CTA) will have unprecedented accuracy and sensitivity, affording us the ability to understand the mysteries of the high energy universe. This unprecedented accuracy does however also force us to adapt current calibration procedures, or indeed pioneer new techniques, to ensure the envisaged CTA performance. CTA will infer the energy of the gamma-rays it detects by...
The young star clusters/star forming regions have been believed to be the Galactic CRs contributors. As the CR acceleration sites, the collective effect of stellar winds and/or supernova activity in the young stellar associations can produce a large-scale shock, which will accelerate the particles up to energies of hundreds of TeV. And these high-energy particles can produce the...
The Moon is among the brightest gamma-ray sources in the sky. We have reconstructed its gamma-ray spectrum in the energy range from 30 MeV up to a few GeV using the data collected by the Fermi Large Area Telescope during its first 13 years of operation since its launch in 2008, a period covering the duration of a whole solar cycle. We have also studied the evolution of the lunar gamma-ray...
The shock wave resulting from the core-collapse of a massive star can accelerate particles up to PeV energies in the first few days to weeks after explosion. This can lead to the production of a potentially detectable gamma—ray signal. The gamma-ray flux however is strongly affected by the two photon—annihilation process, where gamma—ray photons interact with photons from the SN photosphere....
Low-energy cosmic ray antideuterons (< 0.25 GeV/n) are a compelling, mostly uncharted channel of many viable dark matter models, and they benefit from a highly sup-pressed astrophysical background. The General Antiparticle Spectrometer (GAPS) is a first-of-its-kind Antarctic balloon-borne experiment specialized for the detection of low energy antiprotons, antideuterons, and antihelium with a...
The China Seismo-Electromagnetic Satellite (CSES) is a multi-instrumental space mission devoted to the study of the ionosphere, with the main aim to investigate possible correlations between fluctuations of the ionosphere environment and the occurrence of an earthquake. The first satellite (CSES-01) was launched on 2018, while a second one (CSES-02) is currently under development and the...
This contribution describes the Trigger board of the High-Energy Particle Detector, which will be placed onboard the second China Seismo-Electromagnetic Satellite for CSES-Limadou mission.
This mission will monitor variations in ionospheric parameters that are supposed to be related to earthquakes.
The first satellite is already in orbit and the second one will be launched in 2023.
The HEPD...
The High Energy cosmic Radiation detector (HERD) facility has been proposed to be installed onboard the future China’s Space Station (CSS).
HERD will address major problems in fundamental physics and astrophysics with the precise measurement of charged cosmic-rays and gamma-rays from few GeV to PeV energies by means of a large acceptance detector based on an innovative concept.
The...
The China Seismo-Electromagnetic Satellite is a multi-instrument space mission dedicated to the investigation of the topside ionosphere structure and dynamics (plasma parameters, electromagnetic fields and charge particles fluxes) and the possible correlation of its perturbations with the occurrence of high magnitude earthquakes.
The main contribution of the Italian collaboration to the...
CSES-01 (China Seismo-Electromagnetic Satellite) is the first element of an
extended constellation of LEO (Low Earth Orbit) satellites, dedicated to monitoring
perturbations of electromagnetic fields, plasma and charged particle fluxes induced
by natural sources and artificial emitters in the near-Earth space. One of the eight
payloads on board CSES-01 is the Italian High-Energy Particle...
Ultrahigh energy cosmic ray (UHECR) nuclei with Lorentz factors greater than about 10$^9$ lose their energies by the photodisintegration with cosmic microwave background photons in intergalactic space. The photodisintegration is a main process of the energy losses at the highest energies, so it is important to understand the model dependence of the photodisintegration to simulate propagation...
Blazars – active galaxies with the jet pointing at Earth – emit across all electromagnetic wavelengths. The so-called one-zone model has described well both quiescent and flaring states, however it cannot explain the radio emission. In order to self-consistently describe the entire electromagnetic spectrum, extended jet models are necessary. Notably, kinetic descriptions of extended jets can...
China Seismo-Electromagnetic Satellites are the most advanced initiative for the study of the ionosphere-lithosphere coupling from space. They are sensitive to any type of short- to long-lasting perturbations in the ionosphere, thanks to the variety of instruments that they host on board. Among them, the High-Energy Particle Detector is devoted to the observation of electrons and protons with...
We present the current development of the Monitoring, Logging and Alarm subsystems in the framework of the Array Control and Data Acquisition System (ACADA) for the Cherenkov Telescope Array (CTA). The Monitoring System (MON) is the subsystem responsible for monitoring and logging the overall array (at each of the CTA sites) through the acquisition of monitoring and logging information from...
The ASTRI Mini-Array is an international collaboration led by the Italian National Institute for Astrophysics (INAF), aiming to construct and operate an array of nine Imaging Atmospheric Cherenkov Telescopes to study gamma-ray sources at very high energy (TeV) and perform Stellar intensity interferometry observations.
This contribution describes the design and the technologies used by the...
The Circinus galaxy is a nearby composite starburst/active galactic nucleus (AGN) system. In this work we re-analyze the GeV emission from Circinus with 10 years of Fermi-LAT data. Our 0.1–500 GeV flux is several times lower than that reported in previous literature, which is roughly in compliance with the empirical relation for star-forming and Local Group galaxies and might be reproduced by...
The half array of the KM2A in LHAASO has been operated since the end of 2019. It is a major ground-based array for the researches on cosmic rays around knees and the gamma-ray astronomy at ultra-high energy, which depends heavily on its performances. The cosmic-ray Moon shadow, which is observed by KM2A with monthly significance of 25 standard deviation, is used as an unique and powerful...
The High Energy cosmic Radiation Detector (HERD) is one of the prominent space-borne instruments to be installed on board the upcoming Chinese Space Station (CSS) in 2026 and is the result of a collaboration among chinese and european institutions. Primary scientific goals of HERD include: precise measurements of the cosmic ray (CR) energy spectra and mass composition at energies up to few...
The TAIGA (Tunka Advanced Instrument for cosmic ray physics and Gamma Astronomy) observatory is located in the Tunka valley (~50 km west from the southern shore of Lake Baikal) at an altitude of 675m a.s.l. The TAIGA observatory aims to address gamma-ray astronomy at energies from a few TeV to several PeV and CR physics from 100 TeV to several EeV. Its main feature is the complementary, hybrid...
Large research infrastructures have opened new observational windows, allowing us to study the structure of matter up to the entire Universe. However, society hardly observes these developments through education and outreach activities. This induces a gap between frontier science and society that may create misconceptions about the content, context, and mission of public funded science.
In...
The Southern Wide-field Gamma-ray Observatory (SWGO) is a project for a new generation of extensive air shower detectors, based on the water Cherenkov technique, to be located in the Southern Hemisphere, where no other instruments of that kind is currently operating in the TeV energy range. The reference configuration of SWGO foresees an array of about 6,000 water Cherenkov tanks deployed over...
The Cherenkov Telescope Array (CTA) will use three telescope sizes to efficiently detect cosmic gamma rays in the energy range from several tens of GeV to hundreds of TeV. The Small Sized Telescopes (SSTs) will form the largest section of the array, covering an area of many square kilometres on the CTA southern site in Paranal, Chile. Up to 70 SSTs will be implemented by an international...
The search for Primordial Black Hole (PBH) signatures is very broad in techniques and the origin of these signatures. Searches for imprints of evaporation involve several observables such as the Extragalactic Gamma-Ray background or direct measurement of different species of cosmic rays. Using these observables, one can put very tight constraints on the PBH number density in a mass range...
TIGERISS is an Ultra-Heavy Galactic Cosmic Ray (UHGCR) detector to be proposed to the NASA Astrophysics Pioneers program capable of measuring the abundance relative to $_{26}$Fe of every element from $_{5}$B to $_{82}$Pb. It is evolved from the LDB TIGER and SuperTIGER balloon instruments and the Heavy-Nuclei Explorer SMEX, and compared to its predecessors, TIGERISS will have a greatly...
TRISTAN (TRasgo para InveSTigaciones ANtarticas) is a high granularity tracking detector of the Trasgo family. It was developed to complement the other detectors of the ORCA observatory that have been installed in one of the Spanish bases in Antarctica. TRISTAN is composed of three RPC planes (Resistive Plate Chambers) and offers, (i) a surface of 1.8 m2, (ii) a high multiplicity tracking...
The Horizon-T experiment is located at the elevation of 3346 m above sea level near the city of Almaty, Republic of Kazakhstan. A thorough comparison of the spatial and temporal characteristics of charged components of Extended Air Showers (EAS) with delayed particles with the simulated EAS using CORSIKA simulation package has been conducted using the selection from the experimental data set...
The High Energy Stereoscopic System (H.E.S.S.) is an array of five Imaging Atmospheric Cherenkov Telescopes located in the Khomas Highland of Namibia. H.E.S.S. observes gamma rays above tens of GeV by detecting the Cherenkov light that is produced when Very High Energy gamma rays interact with the Earth’s atmosphere. The H.E.S.S. Data Acquisition System (DAQ) coordinates the nightly telescope...
The VERITAS Imaging Air Cherenkov Telescope (IACT) array was augmented in 2019 with high-speed focal plane electronics to allow the use of VERITAS for Stellar Intensity Interferometry (SII) observations. Since January 2019, VSII recorded more than 127 hours of moonlit observations on 22 different bright stars and binary systems ($m_V$ < 3). The observations resulting in the measurement of the...
The one square kilometer array (KM2A), a sub-array of LHAASO experiment, consists of 5195 ED and 1188 MD detectors, has been built over three-quarters scale and began operation since December 2020. Its main scientific goal is to study gamma ray sources at energies above 100 TeV. In this work, an offline self-calibration method was used to calibrate the KM2A-ED array to guarantee the key...
The LHAASO (Large High Altitude Air Shower Observatory) is a multi-purpose experiment for measuring the high energy gamma rays and cosmic rays. One of the major detectors is the 78,000 m2 WCDA (Water Cherenkov Detector Array), equipped with 3120 PMTs, which aims to survey the gamma-ray sky continuously in a wide energy range, from 100 GeV to 30 TeV. Precisely calibrating the time offsets of...
After entering the Galactic cosmic rays (CRs) into the heliosphere, their intensities decrease during their propagation toward the Earth. This effect is subjected to a variety of physical processes through their propagation which referred to as CR solar modulation. The key ingredients in the study of this phenomenon are the knowledge of the local interstellar spectrum (LIS) of Galactic cosmic...
The secondary particles produced during the interaction of primary gamma rays or cosmic rays in the atmosphere can be measured using Water Cherenkov Detectors (WCD).
Detailed simulations of the WCD signals produced by the interactions of the secondaries inside the detector are computationally time consuming, so a fast simulator is desirable.
In this work, we use complete and detailed...
The Multimessenger Diversity Network (MDN), formed in 2018, extends the basic principle of multimessenger astronomy – that working collaboratively with different approaches enhances understanding and enables previously impossible discoveries – to equity, diversity, and inclusion (EDI) in science research collaborations. With support from the National Science Foundation INCLUDES program, the...
Mini-EUSO is a small orbital telescope with a field of view of 44x44 deg, observing the night-time Earth mostly in 320-420 nm band. Its time resolution spanning from microseconds (triggered) to milliseconds (untriggered) and more than 300x300 km of the ground covered, allows it to register thousands of meteors. Such detections make the telescope a suitable tool in the search for hypothetical...
The science education in universities has several deferring moments for the general student population outside of the Physics/Astronomy fields or STEM in general. A large contribution to that comes from the high cost of the textbooks that is typical for the introductory physics and astronomy courses. Another is the lack of supporting class materials, such as audio-video materials and support...
The muons produced by cosmic ray interactions in the upper atmosphere constitute the main background for underwater neutrino detectors such as KM3NeT (the Cubic Kilometre Neutrino Telescope), which is currently being deployed in the Mediterranean Sea at two distinct locations. Situated at different depths, the KM3NeT/ARCA and KM3NeT/ORCA detectors experience a different flux of muons, and thus...
The Tunka-Grande scintillation array is a part of the TAIGA experimental complex designed for high-energy gamma-ray astronomy and cosmic-ray physics.
In this work methods of reconstruction of primary particles parameters are presented, as well as the accuracy of reconstruction of the EAS core position, energy, and arrival direction, obtained by comparing the reconstruction results with the...
The second generation of the Extreme Universe Space Observatory on a Super Pressure Balloon (EUSO-SPB2) is a balloon instrument for the detection of ultra high energy cosmic rays (UHECRs) with energies above 1 EeV and very high energy neutrinos with energies above 10 PeV. EUSO-SPB2 consists of two telescopes: a fluorescence telescope pointed downward for the detection of UHECRs and a Cherenkov...
We propose a new method for the estimation of ultra-high energy cosmic ray (UHECR) mass composition from a distribution of their arrival directions. The method employs a test statistic (TS) based on a characteristic deflection of UHECR events with respect to the distribution of luminous matter in the local Universe modeled with a flux-weighed 2MRS catalog. Making realistic simulations of the...
The CALorimetric Electron Telescope (CALET) has collected over 60 months of uninterrupted data on the flux and spectrum of the Ultra-Heavy (UH) cosmic rays from Z=30 to 40. Using the latest data provided from CALET’s UH trigger, we present a newly developed UH analysis complementary to the ongoing analysis presented at this conference by Zober et al. This work introduces a new Ultra-Heavy...
With the High-Altitude Water Cherenkov Observatory (HAWC), the Large High Altitude Air Shower Observatory (LHAASO), and the future SWGO and CTA observatories, our view of the gamma-ray sky above 100 TeV energies will improve rapidly. It is generally held that emission at such high energies from astrophysical objects unambiguously demonstrates the presence of PeV protons or nuclei, due to the...
High-energy muons loose their energy by ionization, pair production, bremsstrahlung and inelastic interaction with nuclei. The process with the largest uncertainty is the inelastic interaction with nuclei. Since the energy loss is dominated by soft interactions with small momentum transfer, parton distribution functions are not applicable and phenomenological parametrizations have to be used....
Astrophysical neutrino fluxes are often modeled as power laws of the energy. This is reasonable in the case of hadronic sources, but it does not capture the behavior in photohadronic sources, where the spectrum depends on the properties of the target photons on which protons collide. This limits the possibility of a unified treatment of different sources. In order to overcome this difficulty,...
Reconstruction of an EAS seen using non-imaging Cherenkov detectors requires simulating the Cherenkov yield of many EAS’s with given shower parameters. Since Shower Universality parameterizes both the angular distribution and energy distribution of charged particles within a shower, one can calculate the Cherenkov photon yield (at a fixed point) from the Cherenkov cones of electrons. In this...
The origin of the high-energy gamma-ray emission from the Milky Way centre is still unclear and debated because of the impact of systematics afflicting the measurements from current experiments. Several theories and phenomenological models attempt to explain the intricate panorama. The presence of a PeVatron in the Central Molecular Zone or in its vicinity, the contribution of the hard...
The blazar Mrk421 (redshift $z=0.031$) is one of the brightest and closest BL Lac type objects, making it an ideal target to probe blazar physics. We report on an extensive multi-wavelength observing campaign in 2017, during which the intra-band correlation patterns show some disparity and complex behaviours. Observations from several instruments are used to achieve an optimal temporal...
Work on the Offline Framework for the Pierre Auger Observatory was started in 2003 to create a universal framework for event reconstruction and simulation. The development and installation of the AugerPrime upgrade of the Pierre Auger Observatory require an update of the Offline Framework to handle the additional detector components and the upgraded Surface Detector Electronics.
The design...
The Large Volume Detector (LVD) at the INFN Gran Sasso National Laboratory, Italy, is a neutrino observatory designed to study low energy neutrinos from gravitational stellar collapses. The detector, 1000 tons of liquid scintillator, is sensitive to core-collapse supernovae via neutrino burst detection with 100\% efficiency in the Milky Way.
In this paper we discuss methods of the neutrino...
The Owens Valley Radio Observatory- Long Wavelength Array (OVRO-LWA) in Eastern California is currently undergoing an expansion to 352 dual-polarization antennas and new signal processing infrastructure. The upgraded array will operate a full-duty-cycle cosmic ray detector simultaneously with a variety of radio astronomy observations. Expanding the methods introduced in a previous...
Atmospheirc neutrino flux calculation by M. Honda (Honda flux [1]) has used as a flux prediction in many experiments including the oscillation analysis in Super-Kamiokande, and has greatly contributed in the neutrino physics. In this talk, we will present an upgrade of the neutrino flux calculation with accelerator-data-driven modifications.
The dominant uncertainty of the Honda flux arises...
Interactions between cosmic rays and also between cosmic rays and particles of the Cosmic Microwave Background and the Extragalactic Background Light produce charged and neutral pions. The mechanisms that can produce gamma-ray fluxes associated with cosmic rays are the decay of neutral pions, bremsstrahlung, and inverse Compton scattering from pions. These cascading processes show a...
Dwarf spheroidal satellite galaxies (dSphs) are among the best candidates to perform indirect search for DM, having the highest known mass-to-light ratio and being free of gamma-ray emitting sources. The Major Atmospheric Gamma Imaging Cherenkov (MAGIC) telescopes, located on the Canary Island of La Palma, have observed a fair amount of optimal dSphs in the recent years. This is the outcome of...
The cosmic-ray Sun shadow is caused by high-energy charged cosmic rays (CRs) being blocked and deflected by the Sun and its magnetic field, thereby modulating the resulting shadow in both size and shape. Recent Sun shadow observations by ground-based particle observatories have established a novel and potentially fruitful link between solar physics and high-energy particle astrophysics. Most...
A neutron monitor (NM) is a ground- (or sea-) based detector of the flux of cosmic ray particles in space. The high-energy cosmic rays in the GeV primary range interact in the upper atmosphere, producing a cascade of subatomic particles, some of which reach Earth’s surface. A neutron monitor is mostly sensitive to the neutron component of the atmospheric cascade. The standard-design neutron...
Dark matter (DM) is largely believed to be the dominant component of the matter content of the Universe. Astronomical measurements can be utilized to search for Standard Model annihilation or decay products of DM, complementing direct and collider-based searches. Among DM particle candidates, Weakly Interacting Massive Particles (WIMPs) are an attractive one. Their decay or annihilation could...
The gamma-ray blazar TXS 0506+056 was found with an enhanced gamma-ray emission state in spatial and temporal coincidence with the IceCube high energy neutrino event IC170922A. This is the most significant association by far between a high-energy neutrino event and a blazar in a flaring state. Studying the time evolution and spectral behavior of the blazar emission may help in identifying the...
The Galactic Center region hosts a variety of powerful astronomical sourcesand rare astrophysical processes that emit a large flux of non-thermal radiation. We present the analysis of the very-high-energy gamma-ray emission above 2 TeV of the region around the Galactic Center known as the Central Molecular Zone using 125 hours of data taken with the VERITAS imaging-atmospheric Cherenkov...
Imaging Air Cherenkov Telescopes are continuously exposed to varying weather conditions that have short and long-term effects on their response to Cherenkov light from extensive air showers. This work presents the implementation of a throughput calibration method for the VERITAS telescopes taking into account changes in the optical response and detector performance over time. Different methods...
The Radar Echo Telescope (RET) experiment plans to use the radar technique to detect Ultra-High Energy (UHE) cosmic rays and neutrinos in the polar ice sheets. When a UHE particle collides with an ice molecule, it produces a shower of relativistic particles, which leaves behind a trail of plasma in the ice. Radiowaves can be reflected off this plasma and be detected by receiving antennas....
The GRAPES-3 experiment located at Ooty, India, consists of an array of 400 plastic scintillators which records the particle densities and relative arrival times of secondaries in an air shower. The particle densities recorded in individual detectors are then fitted by the well known NKG function to obtain the shower parameters, namely the shower core, age and size. High energy showers with...
We present a catalog of results published from 2008 to 2020 through gamma ray observations made by VERITAS. VERITAS is a ground based imaging atmospheric Cherenkov telescope observatory located at the Fred Lawrence Whipple Observatory (FLWO) in southern Arizona, sensitive to gamma-ray photons with energies in the range of $\sim$ 100 GeV - 30 TeV. Its observation targets include galactic...
X-ray binaries present a particularly interesting class of gamma-ray emitter, with most emitting no detectable gamma-rays at all, and those that are detected falling into two distinct morphological classes: microquasars and gamma-ray binaries. Given the highly variable, and often faint, nature of these systems discovering them represents a unique challenge to the gamma-ray astronomy community,...
The X-ray spectral curvature in high energy peaked BL Lac (HBL) sources has been interpreted in terms of either shock acceleration, where accelerated electrons attain maximum energy (Lorentz factor, $\gamma_{max}$) (Kirk et al.1998,A$\&$A,333,452) and consequently emit synchrotron radiation, or due to energy-dependent electron diffusion from the acceleration regions (Goswami et...
A large area (560 m$^2$) muon telescope in the GRAPES-3 experiment at Ooty, India records muon intensity at high cutoff rigidities (15–24 GV) along 169 independent directions spanning a field of view of 2.3 sr. The threshold energy of the recorded muons is sec(θ) GeV along a direction with a zenith angle (θ) and with the average angular accuracy of ~4°. The directional capabilities of the...
The Cosmic-Ray Extremely Distributed Observatory (CREDO) was established to detect and study ultra high-energy cosmic ray particles. In addition to making use of traditional methods for finding rare and extended cosmic ray events such as professional-grade EAS arrays, as well as educational ‘class-room’ detectors, CREDO also makes use of cameras in smartphones as particle detectors. Beyond the...
Indirect searches for signatures of corpuscular dark matter have been performed using all cosmic messengers: gamma rays, cosmic rays, and neutrinos. The search for dark matter with neutrinos is important since they are the only courier that can reach detectors from dark matter processes in dense environments, such as the core of the Sun or Earth, or the edge of the observable Universe. One...
The outreach program “A scuola di Astroparticelle” was proposed in 2016 by the
National Institute of Nuclear Physics (INFN – Napoli Division) in collaboration with the Physics Department “Ettore Pancini” of the Federico II University in Napoli, CNR-SPIN and CNR-ISASI Institutes. Its main goal is to engage teachers and students of High Secondary Schools in astroparticle physics projects. For...
During a tracking observation, every telescope with an alt-azimuthal mount shows a rotation in the field of view (FoV) due to the diurnal motion of the Earth. The angular extension of the rotation depends mainly on the time-length of the observation, but also on the latitude and the telescope’s pointing direction, as it is determined by the evolution of the parallactic angle of the target.
In...
Transients of the atmospheric electric field could cause anomalous events in the surface particle detectors of cosmic ray observatories. A better understanding of these incidents requires more accurate lightning data at the observation sites. We present the design and implementation of a monitoring system capable of detecting and storing lightning discharges. The acquisition window per event...
The Galactic center is widely anticipated to be an important cosmic-ray source and the observations of some Imaging Atmospheric Cherenkov Telescopes did successfully reveal a new component of TeV-PeV cosmic rays in the vicinity of the Galactic center. This work reports the identification of GeV-TeV cosmic rays in the central molecular zone with the γ-ray observations of the Fermi-LAT. The...
The IceCube Neutrino Observatory, deployed beneath the South Pole, is the largest neutrino telescope in the World. While eight years have passed since IceCube discovered a diffuse flux of high-energy astrophysical neutrinos, the sources of the vast majority of these neutrinos remain unknown. Here, we present a new search for neutrino point sources that improves the accuracy of the statistical...
The Fermi bubbles are structures observed in gamma rays at GeV energies, emanating from the central region of our galaxy and extending up to 8.5 kpc above and below the galactic plane. While initial studies showed a flat brightness across the entire structure, more recent work found a brightening at the base. We perform a template-based search for TeV signals from the northern Fermi bubble...
The Cosmic Ray Extremely Distributed Observatory (CREDO) pursues a global research strategy dedicated to the search for correlated cosmic rays, so-called Cosmic Ray Ensembles (CRE). Its general approach to CRE detection does not involve any a priori considerations and the search strategy encompasses both spatial and temporal correlations, on different scales. Here we search for time clustering...
The gamma-ray emission from stars is induced by the interaction of cosmic rays with stellar atmospheres and photon fields. This emission is expected to come in two components: a stellar disk emission, where gamma-rays are mainly produced in atmospheric showers generated by hadronic cosmic rays, and an extended halo emission, where the high density of soft photons in the surroundings of stars...
Mini-EUSO is the first mission of the JEM-EUSO program located on the International Space Station. One of the main goals of the mission is to provide valuable scientific data in view of future large missions devoted to studying Ultra-High Energy Cosmic Rays (UHECRs) from space by exploiting the fluorescence emission generated by Extensive Air Showers (EAS) developing in the atmosphere. A space...
We present here a unified scenario that connects together three peculiar spectral features recently reported in the spectra of charged cosmic rays (CRs).
The spectral hardening measured by AMS-02 in the hadronic spectra above $\sim 250 \, \mathrm{GeV}$ is here interpreted as a diffusion imprint, and modeled by means of a transport coefficient that smoothly hardens with rigidity.
We...
The Fermi Bubbles (FBs) are two large structures above and below the Galactic Plane. They are first discovered by Fermi-LAT and thought to be related to the jet or the wind from the Galactic center. In this work, we use more than 5 years of DAMPE photon data to analyze the FBs. We calculate the TS values of the FB lobes and the significance of its curved spectrum. The obtained spectral...
In our epoch, images are a powerful way to convey a message to a large audience. Through the use of amazing astronomical photographs, science can be communicated effectively at different levels, to a very diverse audience of all ages. In fact, astrophotography combines aesthetic appeal with the illustration of the science behind astronomical phenomena. This is the aim of the exhibit “A che...
Cosmic rays are ubiquitous and readily available, making them a good teaching tool for particle and astrophysics for young students. ‘Tan-Q’ is an inclusive outreach and educational project, providing students in Japanese junior-high or high schools for research opportunities to join in cosmic-ray and particle physics (PI: K. S. Tanaka). In the Tan-Q framework, the students in each school...
The AMS-02 collaboration released several secondary-to-primary ratios of
unprecedented accuracy. These ratios can be used to test the
universality of propagation for different species, and also to test the
presence of breaks in the diffusion coefficient. It was shown in Weinrich
et al. (A&A 639, 131, 2020) that the combined analysis of Li/C, Be/C,
and B/C strengthens the case for a...
Discovering the secrets of invisible cosmic particles and using them to study the structure of the universe is a citizens' initiative supported by the Cosmic Ray Extremely Distributed Observatory (CREDO). The method of operation is the parallel participation in research of all citizens: experienced scientists and people without scientific experience, aiming to the full immersion of all ages,...
The cosmic-ray propagation in the Galaxy has not yet been understood in detail. The flux ratio of secondary to primary components among the cosmic radiation have been measured by many experiments providing important information to understand the average amount of interstellar material traversed by cosmic rays. However, such ratio cannot strongly constrain another essential parameter of the...
The Alpha Magnetic Spectrometer (AMS-02) has been operating aboard the International Space Station (ISS) since May 2011. Lithium and Beryllium are expected to be mainly produced by the fragmentation of primary cosmic rays (CR) during their propagation. Therefore, their measurement is essential in the understanding of cosmic ray propagation and sources. Their isotopic composition can provide...
The transport of Galactic cosmic rays (CRs), governed by the magnetic collisionless interactions they suffer with interstellar plasma waves, is commonly studied as a diffusive movement, characterised by a diffusion coefficient following a power law as function of rigidity. The accuracy of current CR data allows us to precisely test our propagation models, usually by reproducing the...
The gamma radiation produced in cosmic-ray and gas interactions has been used to probe the cosmic-ray spectrum in several clouds to distances of a few hundred parsecs around the Sun. Early measurements made with Fermi LAT data were found in good agreement with the proton and alpha cosmic-ray spectra measured in the Solar System, given the 10-15% uncertainty in target gas mass that is inherent...
A crucial aspect for outreach activities in cosmic-ray physics is the ability to bring the audience in contact with the experiments and let them visualize the underlying physics. A possible option is the use of portable detectors, which can be easily transported and operated in the various places where outreach activities take place (schools, theaters, etc.), and are equipped with a fast data...
At the Pierre Auger Observatory, designed primarily to study ultra-high-energy cosmic rays, phenomena related to atmospheric electricity are also observed. Particularly peculiar events have been detected with the Surface Detector (SD), characterized by long-lasting signals (tens of microseconds) and event footprints much larger (up to 200 km$^2$) than those produced by the highest energy...
The Galactic gamma-ray diffuse emission is produced by the interaction of cosmic rays with ambient gas and electromagnetic radiation fields in the interstellar medium (ISM). Studying this radiation helps reconstruct the particle transport mechanisms and the particle distribution in the Galaxy. In this work, we analyze TeV emissions in a chosen region of the Galactic plane using data collected...
Galactic cosmic rays propagating in interstellar space interact with gas and radiation fields producing gamma ray and neutrino emissions of comparable intensity. These emissions result in diffuse fluxes of secondary particles reaching the Earth that encode information on the space distribution, energy spectra and mass composition of the parent CR's in the entire volume of the Galaxy, where...
The last decade brought spectacular advances in the astrophysics of cosmic rays (CRs) and gamma-ray astronomy. Improvements in sensitivity of new experiments and other technological breakthroughs allow them to explore unchartered territory, advancing in energy coverage, energy and angular resolutions, and probe subtle signatures of new physics. The accuracy of theoretical models becomes...
Recently, a diffuse emission of 1-100 GeV $\gamma$-rays has been detected from the direction of Andromeda. The emission is centered on the galaxy, and extends for $\sim 100-200$ kpc away from its center. Explaining the extended $\gamma-$ray emission within the framework of standard scenarios for the escape of cosmic rays injected in the galactic disk or in the galactic center is problematic....
The International Particle Physics Group (IPPOG) is a global network active in informal education and outreach in particle physics and related research, including cosmic-ray and astro-particle physics. Since many years, IPPOG has been actively supporting the International Cosmic Day organized by DESY and the International Muon Week organized by Quarknet. In 2015 IPPOG started work on...
In this work, we compute the contribution from clusters of galaxies to the diffuse neutrino background. Clusters of galaxies can potentially produce cosmic rays (CRs) up to very-high energies via large-scale shocks and turbulent acceleration. Due to their unique magnetic-field configuration, CRs with energy $\sim 10^{17}$ eV or smaller can be trapped within these structures over cosmological...
Shock interaction has been argued to play a role in powering a range of optical transients, including supernovae, classical novae, stellar mergers, tidal disruption events, and fast blue optical transients. These same shocks can accelerate relativistic ions, generating high-energy neutrino and gamma-ray emission via hadronic pion production. We introduce a model for connecting the radiated...
With infrared luminosities $L_{\mathrm{IR}} \geq 10^{12} L_{\odot}$, Ultra-Luminous Infrared Galaxies (ULIRGs) are the most luminous objects in the infrared sky. They are predominantly powered by starburst regions with star-formation rates $>\sim 100~ M_{\odot}~ \mathrm{yr^{-1}}$. ULIRGs can also host an active galactic nucleus (AGN). Both the starburst and AGN environments contain plausible...
In the last decade, the space-borne experiment AMS-02 has determined cosmic-ray spectra with unprecedented precision, potentially providing new insights into cosmic-ray propagation in our Galaxy. However, the analysis of this increasingly precise cosmic-ray data requires more careful modeling of systematic uncertainties.
I will review the conclusions from the analysis of the secondary cosmic...
Due to the difficulty of direct measurement of the thunderstorm environment, in particular the electric field strengths, the initial stages of lightning breakdown remain mysterious. The 1994 discovery of Terrestrial Gamma-ray Flashes (TGFs) and their implications for megavolt potentials within thunderclouds has proved to be a valuable source of information about the breakdown process.
The...
The results of cosmic ray measuring experiments such as NUCLEON, HAWC, CREAM-III, DAMPE indicate a change in the index of the cosmic ray spectra near the magnetic rigidity of 10 TV.
Such an inhomogeneity in the regular CR spectra can be explained by several possible reasons: features of CR acceleration, specific features of CR propagation, or a contribution to the CR flux from a nearby...
Interstellar cosmic ray (CR) spectra just outside the heliosphere are accessible thanks to direct measurements of CR, with uncertainties given by the solar modulation. Interstellar CR spectra in the local medium (i.e. within ~1 kpc around the Sun) are indirectly accessible thanks to observations of interstellar emissions in radio/microwaves and in gamma rays produced by CR interactions with...
The NA61/SHINE facility is a multi-purpose experiment located at the H2 beam line of the CERN SPS North Area, with the aim of studying the properties of hadron production in nuclear collisions with fixed targets. Important goals are to measure hadron-nucleus interactions to improve cosmic-ray shower modeling and also to study light, secondary cosmic-ray nuclei production (Li, Be \& B) in the...
The DArk Matter Particle Explorer (DAMPE), a space-based high energy particle detector, has been operated on-orbit for more than five years. The large geometric factor and good charge resolution enable DAMPE to have very good potential to measure cosmic-rays up to 100 TeV. Knowledge of the boron to carbon (B/C) flux ratio is very important in understanding the propagation of cosmic rays,...
CALorimetric Electron Telescope, CALET, has been measuring high-energy cosmic rays on the International Space Station since October 2015. One of the scientific objectives of the CALET mission is the precise measurements of the energy spectra of individual cosmic-ray nuclei and the energy dependence of secondary-to-primary abundance ratio to reveal the detail of the cosmic-ray acceleration and...
Galactic diffuse gamma ray emission (GDE) is introduced by the galactic cosmic rays interacting with the interstellar medium and/or radiation fields. We report the measurements of the GDE in several regions of the Galactic plane with energies ranging from 10 to 100TeV by the half-array of LHAASO-KM2A. A modified equal-zenith angle method is employed for background estimation, in which the...
In June 2019 from the region of Calabria (Italy) our group launched the Stratospheric Balloon MoCRiS (Measurement of Cosmic Ray in Stratosphere) that reached up to 35111 meters. MoCRiS is a didactical project that uses a Light Balloon with a payload of only 2.7 Kg payload box included. The capsule is Lithium-ion batteries operated and fully instrumented with sensors for temperature and...
More than a decade after its discovery, the Fermi GeV excess is still an exciting subject of research. Thus far, an unresolved population of millisecond pulsars (MSPs) in the Galactic bulge shining in gamma rays is the favorite explanation to the excess, but other explanations exist. Data from the Fermi-LAT have been thoroughly studied and, in order to discriminate between the different...
The lack of spatial anisotropies in the sky map distribution of observed cosmic neutrinos hints towards the extra-galactic nature of their major sources. However, strong constraints are imposed by the Fermi-LAT data on the isotropic gamma-ray background regardless of the neutrino production mechanism, suggesting that the observed neutrinos might possibly originate in sources that remain hidden...
The HAWC telescopes has recently revealed new spectra for gamma-ray sources in the Galactic plane. In this talk I will review the possibility of detecting these sources at KM3 detectors. I will consider, with particular emphasis, the 2HWC J1825-134 source. Amongst the HAWC sources, it is indeed the most luminous in the multi-TeV domain and therefore is one of the first that should be searched...
Mini-EUSO is a detector observing the Earth in the ultraviolet band from the International Space Station,from a nadir-facing window, transparent to the UV radiation in the Russian Zvezda module.
The instrument, launched in 2019 as part of the Italian Beyond mission, has a field of view of 44◦, a spatial resolution on the ionosphere of 4.7 km and a sampling rate of 2.5 microseconds.
Mini-EUSO...
The Tibet air shower (AS) array and underground water-Cherenkov-type muon detector (MD) array have been successfully operated since 2014, at an altitude of 4,300m in Tibet, China. The gamma-ray energy and arrival direction are determined by the Tibet AS array, while the MD array enable us to suppress more than 99.9% of background cosmic rays above 100 TeV, by means of counting number of muons...
This work presents the first observation by the Telescope Array Surface Detector (TASD) of the effect of thunderstorms on the development of the cosmic ray showers. Observations of variations in the cosmic ray showers, using the TASD, allows us to study the electric field inside thunderstorms on a large scale without dealing with all the limitation of narrow exposure in time and space using...
The Alpha Magnetic Spectrometer (AMS-02) has been operating aboard the International Space Station (ISS) since May 2011. Deuterons represent about 1% of the single-charged cosmic-ray nuclei. They are mainly produced by fragmentation reactions of primary cosmic 4He nuclei on the interstellar medium and represent a very sensitive tool to verify and constrain CR propagation models in the galaxy....
High-energy $\gamma$ rays originating from interactions of cosmic rays (CRs) with the interstellar medium (ISM) carry direct information about the spatial and spectral distribution of these relativistic particles. Observations of Fermi-LAT of the diffuse gas show enhanced emission in the region around 4 kpc from the Galactic center.
Analyses of the diffuse emission however are performed on a...
The Calorimetric Electron Telescope (CALET), launched to the International Space Station in August 2015 and continuously operating since, measures cosmic-ray (CR) electrons, nuclei and gamma-rays. CALET utilizes its main calorimeter charge detector to measure CR nuclei from $_{1}$H to $_{40}$Zr. In order to maximize the acceptance of the rare ultra-heavy (UH) CR above $_{30}$Zn, a special high...
Precision measurements by the Alpha Magnetic Spectrometer (AMS) on the International Space Station of 3He and 4He fluxes are presented. The measurements are based on 100 million 4He nuclei in the rigidity range from 2.1 to 21 GV and 18 million 3He from 1.9 to 15 GV collected from May 2011 to November 2017. We observed that the 3He and 4He fluxes exhibit nearly identical variations with time....
Precise knowledge of the charge and rigidity dependence of the secondary cosmic ray fluxes and the secondary-to-primary flux ratios is essential in the understanding of cosmic ray propagation. We report the properties of heavy secondary cosmic ray fluorine F in the rigidity R range 2.15 GV to 2.9 TV based on 0.29 million events collected by the Alpha Magnetic Spectrometer experiment on the...
We present precision high statistics measurements of the primary cosmic rays Helium, Carbon, and Oxygen and the secondary cosmic rays Lithium, Beryllium and Boron by the Alpha Magnetic Spectrometer in the rigidity range from 2 GV to 3 TV, based on 150 billion cosmic ray events collected by AMS during the first 8.5 years of operation aboard the International Space Station. The properties of the...
QuarkNet High School teachers and students perform experiments with cosmic ray muons. Their data is available to all on the i2u2.org site; enable measurements of muon flux, speed, and lifetime. The pandemic restricted access to many detectors, so QuarkNet provided virtual resources allowing users to carry out simpler experiments with already uploaded data. Users can also request groups...
TUS (Tracking Ultraviolet Set-up) was the world's first orbital detector of ultra-high-energy cosmic rays (UHECRs), that was launched into orbit on 28th April 2016 as a part of the scientific payload of the Lomonosov satellite. During TUS operation for 1.5 years, its exposure reached ~1200-1400 km$^2$sr yr and the detector measured almost 80 thousands events with a few of them satisfying...
Atmospheric monitoring over the 3000 km$^{2}$ Pierre Auger Observatory can be supplemented by satellite data. Methods for night-time cloud detection and aerosol cross-checking were created using the GOES-16 and Aeolus satellites respectively. The geostationary GOES-16 satellite provides a 100% up-time view of the cloud cover over the observatory. GOES-13 was used until the end of 2017 for...
Recently, evidence for an association between high energy neutrinos
detected by IceCube and radio-selected blazars has been found by
Plavin et al. (2020, 2021). This result was achieved using an all sky
complete sample of 3411 blazars selected on their parsec-scale flux
density at 8 GHz higher than 150 mJy.
We perform an analysis using the same sample of radio-selected blazars
and search...
DeepCore, as a densely instrumented sub-detector of IceCube, extends IceCube's energy reach down to about 10 GeV, enabling the search for astrophysical transient sources, e.g., choked gamma-ray bursts. While many other past and on-going studies focus on triggered time-dependent analysis, we aim to utilize a newly developed event selection and dataset for an untriggered all-sky time-dependent...
Large scale diffuse gamma ray emission, originating from cosmic-ray interactions in the interstellar medium, has now been detected at very high energies (VHE) by various instruments (High Energy Stereoscopic System (H.E.S.S.; 2014), Milagro (Abdo et al. 2008), and the ARGO-YBJ (Bartoli 2015). The gamma ray emission from giant molecular clouds (GMCs) is a direct tracer of the cosmic ray...
The IceCube Neutrino Observatory has detected high-energy astrophysical neutrinos in the TeV-PeV range. These neutrinos have an isotropic distribution on the sky, and therefore likely originate from extragalactic sources. Active Galactic Nuclei (AGN) form a class of astronomical objects which are promising neutrino source candidates given their high electromagnetic luminosity and potential...
While the Fermi Bubbles were discovered about a decade ago by Fermi-LAT as a double-emitting lobe extending up to ~50° in latitude above and below the Galactic Center GC), their origin is still unknown. The H.E.S.S. collaboration is currently performing the first ever survey in TeV gamma rays of the Milky Way inner region: the Inner Galaxy Survey (IGS). The IGS is intended to achieve the best...
The main goal of the ANTARES neutrino telescope is the identification of neutrinos from astrophysical sources. Thanks to its location in the Northern hemisphere, ANTARES can rely on an advantageous view of the Southern Sky, in particular for neutrino energies below 100 TeV. This feature, combined with a very good angular resolution for high-quality selected events, makes the telescope an...
Cosmic-ray (CR) sources temporarily enhance the relativistic particle density in their vicinity over the background distribution accumulated by the past injection activity and propagation. If individual sources are close enough to the solar system, their localised enhancements may present as features in the measured spectra of the CRs and in the associated secondary electromagnetic emissions....
The propagation distances of MeV cosmic rays is significantly limited due to ionisation loss in the interstellar medium. Therefore, the density of cosmic rays will depend sensitively on the exact distribution of the sources in space and time. For an ensemble of source distributions, the fluxes will follow a strongly non-Gaussian distribution. Here, we show that the typical flux, that is the...
Significant spectral hardening at around 200 GV magnetic rigidity has been reported by AMS-02, ATIC-2, CALET, CREAM, and PAMELA. This has been observed in high-accuracy measurements of various nuclei energy spectra of both primaries and secondaries. To explain the spectral hardening while maintaining proper B/C and p/He ratios, we study 3 approaches in a reacceleration model: adding a...
Since 2013, the four sites of the Fluorescence Detector (FD) of the Pierre Auger Observatory record ELVES with a dedicated trigger. These UV light emissions are correlated to distant lightning strikes. The length of recorded traces has been increased from 100 $\mu$s (2013), to 300 $\mu$s (2014-16), to 900 $\mu$s (2017-present), to progressively extend the observation of the light emission...
The Pierre Auger Observatory is used to study the extensive air-showers produced by cosmic rays above 10$^{17}$ eV. The Observatory is operated by a Collaboration of more than 400 scientists, engineers, technicians and students from more than 90 institutions in 18 countries.
The Pierre Auger Collaboration is committed to the public release of data for the purpose of re-use by a wide...
The GRAPES-3 experiment reported the measurement of 1.3 GV potential across one of the massive thunderclouds recorded on 1 December 2014 by making use of the muon imaging technique. This measurement is ten times larger than the maximum potential reported previously by balloon and rocket sounding measurements, verifying the almost a century old prediction by C.T.R. Wilson. These measurements...
Ground-based cosmic ray observatories generally record the information on the arrival time and location of each hit to reconstruct the primary direction of the shower event. During thunderstorms, the direction of secondary charged particles is changed due to the acceleration and deceleration of the particles when they cross layers of electric field. The thunderstorm field also has a secondary...
At Aragats research station we are consistently applying methods of particle physics and nuclear spectroscopy for revealing details of the operation of electron accelerators emerging just above our heads in the thunderclouds. The newly emerging field of high-energy physics in the atmosphere needs successive application of experimentation paired with the simulation of physical processes with...
GRBs are the most energetic electromagnetic events in the Universe. Those whose typical duration is longer than a few seconds are known as long GRBs and shorter than a few seconds are short GRBs. It is widely accepted that these events are associated with the collapse of a very massive star and the neutron star (NS) binary merger, respectively. A fast-spinning, strongly magnetized NS could be...
The progenitors of gamma-ray bursts (GRBs) are massive stars still immersed in dense stellar clusters.
We consider a scenario in which protons accelerated within the jet of GRB can escape to dense regions.
Protons interact efficiently with the matter of the cluster and produce high energy neutrinos. We calculate the spectra of relativistic protons within the cluster and spectra of...
Shock acceleration by the shells of supernova remnants (SNRs) has been hypothesized to be the mechanism that produces the bulk of Galactic Cosmic Rays, possibly up to PeV energies. Some SNRs have been shown to accelerate cosmic rays to TeV energies and above. But which SNRs are indeed efficient accelerators of protons and nuclei? And what is the maximum energy up to which they can efficiently...
A large-volume liquid scintillator neutrino detector is proposed to develop at the Baksan Neutrino Observatory of Institute for Nuclear Research of the Russian Academy of Sciences in the North Caucasus. The detector will be located at the depth of 4700 m.w.e. (meter of water equivalent). A target mass of the detector will be 10 kt. This multipurpose detector is being developed to study...
The GRAPES-3 experiment is designed to perform precision studies of gamma-ray sources in the TeV-PeV energy region. It consists of 400 plastic scintillator detectors spanning an effective area of 25000 m$^2$ and a large area (560 m$^2$) muon telescope which records 4x10$^9$ muons every day. With the recent installation of an improved triggerless data acquisition (DAQ) system, the information...
The well-known supernova remnant (SNR) W 44 is observed in high-energy gamma-rays and widely studied to investigate cosmic ray (CR) acceleration. Several analyses of the W 44 surroundings showed the presence of gamma-ray emission offset from the radio SNR shell. This emission is thought to originate from escaped high-energy CRs.
We present a detailed analysis of the W44 region as seen by...
Gamma-ray searches have long been used to constrain the properties of particle dark matter (DM) candidates. In this context, significant effort has been focused in the past decades on the vanilla weakly interacting massive particle (WIMP) DM scenario in which DM particles annihilate through a velocity-independent (s-wave) process. However, in the absence of clear-cut observational evidence for...
ALPACA is a project to construct an air shower array near the Chacaltaya mountain at an altitude of 4,740m in Bolivia. A 83,000 m^2 surface area is covered by 400 scintillating counters of 100cmx100cmx5cm (thick). In addition to this conventional surface array, underground muon detectors covering total 4,000 m^2 allow clear identification of muon components in air showers. Using this array...
Dwarf irregular (dIrr) galaxies have been shown to be dark matter (DM) dominated systems and proposed as interesting targets for the indirect search for DM with gamma rays. In this work, we analyze 11 years of Fermi-LAT data corresponding to the sky regions of 7dIrrs at a distance of less than ~1 Mpc. Due to the current uncertainty in the DM density distribution in these objects, we consider...
Kepler's supernova remnant (SNR) which is produced by the most recent naked-eye supernova in our Galaxy is one of the best studied SNRs, but its gamma-ray detection has eluded us so far. Observations with modern imaging atmospheric Cherenkov telescopes (IACT) have enlarged the knowledge about nearby SNRs with ages younger than 500 years by establishing Cas A and Tycho's SNRs as very high...
Silicon photo-multipliers (SiPMs) have become the baseline choice for cameras of the small-sized telescopes (SSTs) of the Cherenkov Telescope Array (CTA), as the pioneering work of the FACT telescope and the prototypes of SSTs have demonstrated. On the other hand, covering larger surfaces and operating at higher data rates still represent a challenge for SiPMs to surpass photo-multiplier tubes...
As an underground multi-purpose neutrino detector with 20 kton liquid scintillator, Jiangmen Underground Neutrino Observatory (JUNO) is competitive with and complementary to the water-Cherenkov detectors on the search for the diffuse supernova neutrino background (DSNB). Typical supernova models predict 2-4 events per year within the optimal observation window in the JUNO detector. The...
ALTO/COMET is an R&D project aiming to design a very-high-energy (VHE) gamma-ray observatory sensitive to energies above ~200 GeV. The science goals include continuous observation of soft-spectrum VHE gamma-ray sources such as Active Galactic Nuclei and transients such as Gamma-Ray Bursts. With these objectives, ALTO/COMET is designed to have a low energy threshold with a wide field-of-view of...
The proposed GRAMS (Gamma-Ray and AntiMatter Survey) experiment aims to provide unprecedented sensitivity to a poorly-explored region of the cosmic gamma-ray spectrum from 0.1-100 MeV, often referred to as the “MeV gap”. Utilizing Liquid Argon Time Projection Chamber (LArTPC) technology to detect these MeV gamma rays, GRAMS has the potential to uncover crucial details behind a variety of...
In this talk we describe in detail the feasibility of detecting $^8$B solar neutrino at JUNO with three reaction channels (neutrino-electron elastic scattering, neutrino-$^{13}$C charged current, and neutral current interactions). A reduced 2 MeV threshold on the recoil electron energy is achievable with optimized background reduction strategies. The advantage of JUNO for charge and neutral...
We use our time-dependent acceleration code RATPaC to study the formation of extended gamma-ray halos around supernova remnants and the morphological implications that arise when the high-energetic particles start to escape from the remnant.
We performed spherically symmetric 1-D simulations in which we simultaneously solve the transport equations for cosmic rays, magnetic turbulence, and...
Supernova remnants are known to accelerate cosmic rays from their non-thermal emission of radio waves, X-rays, and gamma rays. However, the ability to accelerate cosmic rays up to PeV energies has yet to be demonstrated. The presence of cutoffs in the gamma-ray spectra of several young SNRs led to the idea that PeV energies might only be achieved during the earliest stages of a remnant's...
The supernova remnant (SNR) G35.6−0.4 shows a non-thermal radio shell, however, no gamma-ray or X-ray counterparts have been found for it thus far. One TeV source, HESS J1858+020, was found near the SNR and this source is spatially associated with some clouds at 3.6 kpc. With the Fermi-LAT analysis, we found a hard GeV source (SrcX2) that is spatially coincident with both HESS J1858+020 and a...
The ISS-based Calorimetric Electron Telescope (CALET) is directly measuring the energy spectrum of electron+positron cosmic rays up to 20 TeV. Cosmic-ray electrons of TeV region energy are limited by energy loss to a propagation range of about 1 kpc, therefore the expected sources are a few nearby supernova remnants (SNR), with the Vela SNR dominating the spectrum [Kobayashi et al. 2004]....
JUNO will be a multi-purpose underground neutrino observatory being constructed in the south of China. The JUNO detector, with a 20 kton liquid scintillator target instrumented with about 18k 20'' PMT and about 26k 3'' PMT, will be strategically located 53 km from the Taishan and Yangjiang Nuclear Power Plants. Using reactor antineutrinos, JUNO will be able to measure several neutrino...
Primordial Black Holes are expected to be formed in the early Universe by the gravitational collapse of overdense regions, among other mechanism. They are also expected to loose their mass over time by the Hawking radiation process. As the rates of this radiation increase with temperature, the PBH evaporation should result in a violent explosion.
The current upper limits on explosion rates...
Supernova remnant LMC N132D is a remarkably luminous gamma-ray emitter at ~ 50 kpc with an age of $\sim$2500 years. It belongs to the small group of oxygen-rich SNRs, which includes Cassiopeia A and Puppis A. N132D is interacting with a nearby molecular cloud. By adding 102 hours of new observations with the High Energy Stereoscopic System (H.E.S.S.) to the previously published data with...
We present two results of a search for MeV-scale neutrino and anti-neutrino events correlated with gravitational wave events/candidates and large solar flares with KamLAND.
The KamLAND detector is a large-volume neutrino detector using liquid scintillator, which is located at 1 km underground under the top of Mt. Ikenoyama in Kamioka, Japan.
KamLAND has multiple reaction channels to detect...
We describe the Muography Program to study the Colombian volcanoes. Mainly, we discuss the adopted criteria for designing, building, and commissioning MuTe: a hybrid Muon Telescope. MuTe implements a composite detection technique combining a hodoscope for particle tracking and a water Cherenkov detector for enhancing the muon-to-background-signal separation due to the high energy...
We use FLUKA to study the production of neutrons in extensive air showers. In contrast to typical shower simulations, we consider the full range of neutron energies extending down to thermal neutrons. The importance of different neutron production mechanisms and their impact on the predicted neutron distributions in energy, lateral distance, and arrival time are discussed and compared with...
A signification fraction of Galactic massive stars ($\ge 8\,\rm M_{\odot}$) are ejected from their parent cluster and supersonically sail away through the interstellar medium (ISM). The winds of these fast-moving stars blow asymmetric bubbles thus creating a circumstellar environment in which stars eventually die with a supernova explosion. The morphology of the resulting remnant is largely...
It is widely believed that supernova remnants (SNRs) are the main accelerators of Galactic cosmic rays (CRs) with energies up to the knee. Gamma-ray observations of SNRs is crucial to investigate the particle acceleration process and the origin of Galactic CRs. HESS J1614-518 is a TeV gamma-ray source discovered by H.E.S.S., and show a shell-like morphology in TeV band. Since no associated...
The Water Cherenkov Detector Array (WCDA) is one of the major component of the Large High Altitude Air Shower Observatory (LHAASO). WCDA, divided into 3 separate arrays, will make the survey observation on the gamma-ray sky of 100 GeV - 30TeV. The first array (150m×150m), denoted as WCDA-1, has already be operated in April, 2019 and one more array of the same size, referred to as WCDA-2, has...
Primordial black holes (PBHs), hypothesized to be the result of density fluctuations during the early universe, are candidates for dark matter. When microlensing background stars, they cause a transient apparent enhancement of the flux. Measuring these signals with optical telescopes is a powerful method to constrain the PBH abundance in the range of $10^{-11}\,M_{\odot}$ to...
The Pacific Ocean Neutrino Experiment (P-ONE) is a new initiative to construct one of the world’s largest neutrino detectors in the deep Pacific Ocean off the coast of British Columbia, Canada. Located in the Cascadia Basin region, P-ONE builds on a number of key strengths within the Canadian oceanographic community. The Cascadia Basin monitoring site is part of the NEPTUNE observatory of...
The escape process of particles accelerated at supernova remnant (SNR) shocks is here studied with a phenomenological approach which allows to quantify its impact on the CR spectrum observed on Earth as well as on the gamma-ray spectral signatures emerging from these sources. Under the assumption that in the spatial region immediately outside of the remnant the diffusion coefficient is...
In October 2019 the central 28m telescope of the H.E.S.S. experiment has been upgraded with a new camera. The camera is based on the FlashCam design which has been developed in view of a possible future implementation in the medium-sized telescopes of the Cherenkov Telescope Array (CTA), with emphasis on cost and performance optimization and on reliability. The fully digital design of the...
JUNO is an underground neutrino observatory under construction in Jiangmen, China. It uses 20kton liquid scintillator as target, which enables it to detect supernova burst neutrinos of a large statistics for the next galactic core-collapse supernova (CCSN) and also pre-supernova neutrinos from the nearby CCSN progenitors. All flavors of supernova burst neutrinos can be detected by JUNO via...
Hyper-Kamiokande is a multi-purpose next generation neutrino experiment.
The detector is a two-layered cylindrical shape ultra-pure water tank, with its height of 64 m and diameter of 71 m.
The inner detector will be surrounded by 40,000 twenty-inch photosensors to detect water Cherenkov radiation due to the charged particles and provide our fiducial volume of 187 kt.
This detection...
The detection of the radio emission following a neutrino interaction in ice is a promising technique to obtain significant sensitivities to neutrinos with energies above 10 PeV. The detectable radio emission stems from particle showers in the ice. So far, detector simulations have considered only the radio emission from the primary interaction of the neutrino. We present how the simulation code...
With the knowledge and statistical power of over a decade and a half of measurements, the Auger Collaboration has developed, assessed, and refined robust methods for reconstructing the energies and arrival directions of the highest-energy cosmic rays from the signal and timing measurements of its surface detector array. Concurrently, the unearthing of an increasingly complex astrophysical...
The volcanoes surrounding the HAWC observatory provide varying material depths from open sky to over 15 km of rock for nearly-horizontal muon trajectories. The measurement of the rate of muons as a function of arrival direction near the horizon thereby provides a means to measure the muon flux as a function of material depth. A Hough transform algorithm is used to identify nearly-horizontal...
Supernova remnants (SNRs) are considered one of the best candidates to accelerate the bulk of Galactic cosmic rays. Studying gamma-ray emission from young SNRs allows us to understand the nature of accelerated particles and the maximum energy they can reach. The SNR G150.3+4.5 was recently detected in radio and exhibits a shell-like morphology with an angular size of 3°, suggesting either an...
We analyze the data of Chandra and XMM-Newton in the region of SNR G106.3+2.7 and find the spectrum is dominated by non-thermal X-ray radiation of electrons. The X-ray surface brightness profile of the SNR indicates that the X-ray-emitting electrons in the tail region of the SNR is accelerated by the SNR shock, implying the SNR is an efficient particle accelerator. Based on the multiwavelength...
Cosmological N-body simulations show that Milky-Way-sized galaxies harbor a population of unmerged dark matter subhalos. These subhalos could shine in gamma rays and be eventually detected in gamma-ray surveys as unidentified sources. We search for very-high-energy (VHE, E ≥ 100 GeV) gamma-ray emission using H.E.S.S. observations carried out on a thorough selection of unidentified Fermi-LAT...
$\Lambda$CDM predicts the existence of dark matter (DM) subhalos, most of them not massive enough to retain gas (i.e., baryons) and become visible. If DM is composed of Weakly Interacting Massive Particles (WIMPs), we expect them to annihilate in subhalos, producing gamma rays which can be detected with the Large Area Telescope (LAT) onboard the Fermi satellite, and appearing as unidentified...
Primordial Black Holes (PBHs) have been proposed as a Dark Matter (DM) candidate. Even if they constitute only a component of the DM, their detection would have major implications for fundamental Physics. If a component of the DM is in the form of PBHs, we expect a significant portion of this black hole population to be present at the center of our Galaxy, a region rich of dense molecular...
In this work, we study the potential of the Cherenkov Telescope Array (CTA) for the detection of Galactic dark matter (DM) subhalos. We focus on low-mass subhalos that do not host any baryonic content and therefore lack any multiwavelength counterpart. If the DM is made of weakly interacting massive particles (WIMPs), these dark subhalos may thus appear in the gamma-ray sky as unidentified...
In this work, we carry out a suite of specially-designed numerical simulations that employ a supercluster computational power to shed further light on dark matter (DM) subhalo survival at mass scales relevant for gamma-ray DM searches, a topic subject to intense debate nowadays. Specifically, we have employed a GPU N-body code to study the evolution of low-mass subhalos inside a Milky Way-like...
Abstract: The Southern Wide-view Gamma-ray Observatory (SWGO) will be a next-generation gamma-ray observatory using a large array of particle detectors at a high elevation site in South America. This project is currently in a three years R&D phase in which the design will be optimised for cost and performance. Therefore it is crucial to efficiently evaluate the impact of different design...
The IceCube neutrino observatory opened the window on high-energy neutrino astronomy by confirming the existence of PeV astrophysical neutrinos and identifying the first compelling astrophysical neutrino source in the blazar TXS0506+056. Planning is underway to build an enlarged instrument, IceCube-Gen2, which will extend measurements to higher energies, increase the rate of observed cosmic...
The next generation of the IceCube Neutrino Observatory, IceCube-Gen2, will constitute a much larger detector, increasing the rate of high-energy neutrinos. IceCube-Gen2 will address the long-standing questions about astrophysical accelerators. The experiment will also include a surface air-shower detector which will allow for measurements of cosmic rays in the energy region where a transition...
Preliminary results from the analysis of first data from hybrid observation campaigns using a compact light-weight Refractive Imaging Air-Cherenkov Telescope (RIACT), named HAWC’s eye, and the High-Altitude Water Cherenkov (HAWC) Observatory have shown that some features of the air-shower detection in HAWC, as the angular resolution, could be enhanced. Therefore an array of such devices could...
From new electronics to changes in the PMT configuration, Super-Kamiokande (SK) has undergone several major phases along its history. The latest one, SK-VI, has been the dissolution of 13 tons of gadolinium sulfate octa-hydrate in the hitherto ultra-pure water. The goal of this new phase is to achieve a high neutron efficiency detection. This new capability allows to distinguish different...
Recent results obtained with gamma-ray satellites have established supernova remnants as accelerators of GeV hadronic cosmic rays, which produce detectable gamma-ray emission through interaction with particles from gas clouds in their surrounding. In particular, the rich medium in which core-collapse SNRs explode provides a large target density to boost hadronic gamma-rays. SNR G39.2-0.3 is...
Recent findings by the LHAASO experiment are opening a new window, that of the PeV sky, to the observation of the electromagnetic spectrum.
Several astronomical objects emitting gamma-rays at energies well above 100 TeV have been observed with the LHAASO-KM2 array of scintillators and muon detectors, clearly demonstrating the feasibility of gamma-ray astronomy up to PeV energies.
An all-sky...
The Hyper-Kamiokande project is a 260-kton Water Cherenkov together with an upgraded high-intensity neutrino beam from J-PARC. The inner detector with the 190-kton fiducial volume is viewed by 20-inch PMTs and multi-PMT modules providing state-of-art of Cherenkov ring reconstruction with a few MeV energy thresholds. Thanks to the further improvements of systematic errors with near detector...
The Large Size Telescopes (LSTs) of Cherenkov Telescope Array (CTA)
are designed for gamma-ray studies focusing on low energy threshold,
high flux sensitivity, rapid telescope repositioning speed and a large field of view. Once the CTA array is complete the LSTs will be dominating the CTA performance between 20 GeV and 150 GeV. During the CTA North construction phase, however, the LSTs will...
MACE (Major Atmospheric Cherenkov Experiment) is an imaging atmospheric Cherenkov telescope which has recently been installed by the HiGRO (Himalayan Gamma-Ray Observatory) collaboration at Hanle (32.80N, 78.90E, 4270m asl) in Ladakh region of North India. The telescope has a 21m diameter large light collector consisting of indigenously developed 1424 square shaped diamond tuned spherical...
The ASTRI MINI-ARRAY is an international project led by the Italian National Institute of Astrophysics (INAF) with the participation of the Instituto de Astrofisica de Canarias, Brazil and South Africa to be installed at the Teide Observatory, in Tenerife, to observe the Very High Energy sky in the range of a few TeV up to 100 TeV and beyond. The ASTRI MINI-ARRAY technology is based on the...
The Carpet-3 extensive air shower array is now under construction at the Baksan Neutrino Observatory. The array is located at an altitude 1700 meters above sea level, and it consists of surface detection stations, situated close to each other for best sensitivity to extensive air showers with lower energy, and of an underground muon detector with a continuous area of 410 sq. m. The energy...
The shadow of the moon observed with cosmic rays offers a good ability to
do Energy scale calibration below a few TeV. Water Cherenkov Detector Array
(WCDA), one of components of Large High Altitude Air Shower Observation
(LHAASO), has lower threshold, and high duty cycle, which make itself a very good
facility in this particular aspect. In this presentation, a work to study the energy...
The Radar Echo Telescope for Cosmic Rays (RET-CR) is a pathfinder experiment for the Radar Echo Telescope for Neutrinos (RET-N), a next-generation in-ice detection experiment for ultra high energy neutrinos. RET-CR will serve as the testbed for the radar echo method to probe high-energy particle cascades in nature, whereby a transmitted radio signal is reflected from the ionization left in its...
We present the Radar Echo Telescope for Neutrinos (RET-N). RET-N focuses on the detection of the cosmic neutrino flux at >PeV energies by means of the radar detection technique. This method aims to bridge the energy gap between the diffuse neutrino flux detected by IceCube up to a few PeV and the sought for cosmogenic neutrinos at EeV energies by the in-ice Askaryan detectors, as well as the...
We estimate the sensitivity of the Cherenkov Telescope Array (CTA) to detect diffuse gamma-ray emission from the Perseus galaxy cluster, both from interactions of cosmic rays (CR) with the intra-cluster medium, or as a product of annihilation or decay of dark matter (DM) particles in case they are weakly interactive massive particles (WIMPs). The observation of Perseus constitutes one of the...
The physical motivations and performance of the TAIGA (Tunka Advanced Instrument for cosmic ray physics and Gamma Astronomy) project are presented. The TAIGA observatory addresses ground-based gamma-ray astronomy at energies from a few TeV to several PeV, as well as cosmic ray physics from 100 TeV to several EeV and astroparticle physics. The pilot TAIGA complex locates in the Tunka valley,...
A very small fraction of (runaway) massive stars have masses exceeding $60$-$70\, \rm M_{\odot}$ and are predicted to evolve as Luminous-Blue-Variable and Wolf-Rayet stars before ending their lives as core-collapse supernovae. Our 2D axisymmetric hydrodynamical simulations explore how a fast wind ($2000\, \rm km\, \rm s^{-1}$) and high mass-loss rate ($10^{-5}\, \rm M_{\odot}\, \rm yr^{-1}$)...
Emission from electron-positron annihilation at 511 keV was the first extrasolar gamma-ray line ever detected. Despite more than 30 years of theoretical and observational progress, the origin of the positron population has yet to be identified, with potential candidates ranging from microquasars and X-ray binaries to annihilation or decay of dark matter particles.
At energies between 200 keV...
The origin of ultrahigh-energy cosmic rays (UHECRs) still remains mystery. It has been suggested that UHECRs can be produced by the stochastic acceleration in relativistic jets of gamma-ray bursts (GRBs) at the early afterglow phase. Here, we propose a time-dependent model for proton energization by cascading compressible waves in GRB jets with concurrence of the jet’s dynamics and the mutual...
Recent detections of gravitational wave signals and neutrinos from gamma-ray sources have ushered in the era of multi-messenger astronomy, while highlighting the importance of gamma-ray observations for this emerging field. AMEGO-X, the All-sky Medium Energy Gamma-Ray Observatory eXplorer, is an MeV gamma-ray instrument that will survey the sky in the energy range from hundreds of keV to one...
The recent discovery of electromagnetic signals in coincidence with gravitational waves from neutron-star mergers has solidified the importance of multimessenger campaigns for studying the most energetic astrophysical events. Pioneering multimessenger observatories, such as the LIGO/Virgo gravitational wave detectors and the IceCube neutrino observatory, record many candidate signals that fall...
BurstCube is a CubeSat Gamma-Ray Burst (GRB) detector expected to launch in 2022, significantly expanding sky coverage in the ~50 keV to 1 MeV energy range and increasing the probability of detecting a gravitational wave counterpart. BurstCube will take advantage of the Tracking and Data Relay Satellite (TDRS) system in order to provide rapid public alerts and localization information, which...
We present searches for ultra-high energy (UHE) neutrinos ($> 0.1$ EeV) with the Pierre Auger Observatory, following up binary black hole (BBH) mergers detected by the LIGO and Virgo detectors via gravitational waves. In this work, the so-far published BBH mergers are combined as variable standard candles with a hypothetical isotropic UHE neutrino luminosity $L(t-t_0)$ as a function of the...
Lorentz symmetry requires the space-time structure to be the same for all observers, but, on the other hand, various quantum gravity theories suggest that it may be violated when approaching the Planck scale. Even a small violation of Lorentz Invariance (LI) could easily affect the Ultra High Energy Cosmic Rays (UHECRs) propagation on a cosmological scale. Moreover, at the extreme energies,...
The detection of an extended multi-TeV gamma ray emission around the
Geminga pulsar by the HAWC collaboration provides a unique tool to investigate the transport properties of cosmic rays in the turbulent magnetized interstellar medium.
In this work, different regimes of propagation of ultrarelativistic
electrons in the proximity of pulsars are analyzed and their implications
for the...
Highly extended gamma-ray emission around the Geminga pulsar was discovered by Milagro and verified by HAWC. Despite many observations with Imaging Atmospheric Cherenkov Telescopes (IACTs), detection of gamma-ray emission on angular scales exceeding the IACT field-of-view has proven challenging. However, recent developments in analysis techniques have enabled the detection of significant...
Despite several decades of multi-wavelength and multi-messenger spectral observations, Gamma-Ray Bursts (GRBs) remain one of the big mysteries of modern astrophysics. Polarization measurements are essential to gain a more clear and complete picture of the emission processes at work in these extremely powerful transient events. In this regard, a first generation of dedicated gamma-ray...
HESS J1857+026 is an extended gamma-ray source discovered by H.E.S.S., and identified as a pulsar wind nebula (PWN) candidate associated with PSR J1856+0245. MAGIC performed a follow-up observation, and two gamma-ray sources, called MAGIC J1857.2+0263 and MAGIC J1857.6+0297, were detected above 1 TeV. Taking advantage of 11 years of Fermi-LAT data, we re-analyze the region around HESS...
The discovery of the electromagnetic counterpart AT2017gfo and the GRB 170817A, associated to the binary neutron star merger GW170817, was one of the major advances in the study of gamma-ray bursts (GRBs) and the hallmark of the multi-messenger astronomy with gravitational waves. Another breakthrough in GRB physics is represented by the discovery of the highly energetic, teraelectronvolt (TeV)...
Super-Kamiokande (SK) is a 50-kt water Cherenkov detector, instrumented with ∼13k photomultipliers and running since 1996. It is sensitive to neutrinos with energies ranging from 4.5 MeV to several TeV. A new framework has been developed for the follow-up of gravitational wave (GW) alerts issued by the LIGO-Virgo collaboration (LVC). Neutrinos are searched for, using a 1000-second time window...
The field of multimessenger astronomy has become increasingly important during the past decade. Some astronomical objects have already been successfully observed in the light of multiple messenger signals, allowing for a much deeper understanding of their physical properties. The Pierre Auger Observatory has taken part in multimessenger astronomy with an exhaustive exploration of the...
The CALorimetric Electron Telescope (CALET) has been observing high energy cosmic rays and gamma-rays on the International Space Station since October 2015. The Calorimeter (CAL), the primary instrument of the CALET, has been collecting high-energy gamma-ray data above 1 GeV. The CALET gamma-ray burst monitor (CGBM), utilizing bismuth germanate and lanthanum bromide scintillation detectors, is...
The High Energy cosmic-Radiation Detection (HERD) facility has been proposed as a space astronomy payload onboard the future China’s Space Station. HERD is planned for operation starting around 2025 for about 10 years In addition to the unprecedented sensitivity for dark matter searches and cosmic-ray measurements up to the knee energy, it should perform gamma-ray monitoring and full sky...
We are developing a GRAINE project, 10 MeV – 100 GeV cosmic $\gamma$-ray observations with a precise (0.08 degree @ 1 – 2 GeV) and polarization sensitive large-aperture-area ($\sim$10 m$^2$) emulsion telescope repeated long duration balloon flights. We demonstrated a feasibility and performance of the balloon-borne emulsion $\gamma$-ray telescope experiment with various test experiments and...
The IceCube DeepCore is a dense infill array of the IceCube Neutrino Observatory at the South Pole. While IceCube is best suited for detecting neutrinos with energies of several 100 GeV and above, DeepCore allows to probe neutrinos with lower energies. We focus on a sample of neutrinos with energies above approximately 10 GeV, which was originally optimised for oscillation experiments....
Binary black hole (BBH) mergers are not obviously expected to emit electromagnetic radiation. However, hints of a short gamma-ray burst (GRB), temporally coincident with the GW150914 BBH merger event, sparked much interest and controversy, and inspired new models to explain a potential relation between BBH mergers and GRBs. To put these models to the test BBH follow-up observations across the...
Despite the impressive progresses achieved both by X-ray and gamma-ray observatories in the last decades, the energy range between $\sim 200\,\mathrm{keV}$ and $\sim 50\,\mathrm{MeV}$ remains poorly explored. COMPTEL, on-board CGRO (1991-2000), was the last telescope to accomplish a complete survey of the MeV-sky with a relatively modest sensitivity. Missions like AMEGO have been proposed for...
Some Quantum Gravity (QG) theories, aiming at unifying general relativity and quantum mechanics, predict an energy-dependent modified dispersion relation for photons in vacuum leading to a Violation of Lorentz Invariance (LIV). One way to test these theories is to monitor TeV photons time-of-flight emitted by distant, highly energetic and highly variable astrophysical sources such as flaring...
Recently, gamma-ray halos of a few degree extension have been detected around two middle-aged pulsars, namely, Geminga and PSR B0656+14, by the High Altitude Water Cherenkov observatory (HAWC). The gamma-ray radiation arise from relativistic electrons that escape the pulsar wind nebula and diffuse in the surrounding medium. The diffusion coefficient is found to be significantly lower than the...
Detecting astrophysical events through multiple messengers improves our understanding of underlying sources. In addition to probing different physics, multi-messenger observations can provide improved localization in low latency, guiding astronomers who perform follow-up observations. We will present the real-time and offline searches for high-energy neutrinos associated with...
We present a novel concept for a next-generation γ-ray telescope that will cover the hard X-ray - soft γ-ray region. Despite the progress made by the European Space Observatory INTEGRAL, this energy range is still under-explored. GECCO will conduct high-sensitivity measurements of the cosmic γ-radiation in the energy range from 50-100 keV to ∼10 MeV and create intensity maps with high spectral...
Gamma-ray halos around pulsars at very-high energies are an effective probe of particle propagation in the interstellar medium. Using the data collected by the half-array of the Large High Altitude Air Shower Observatory (LHAASO), we study the morphologies and spectra of the >25 TeV gamma-ray emission around Geminga and Monogem. The significance of Geminga (Monogem) above 25 TeV is ~10sigma...
We study electron and positron acceleration at the termination shock of a striped pulsar wind by integrating particle trajectories in a prescribed model of the magnetic field and flow pattern. We find that drift motion on the shock surface maintains either electrons or positrons on Speiser orbits in a ring-shaped region close to the equatorial plane of the pulsar, where they are accelerated to...
GRAMS (Gamma-Ray and AntiMatter Survey) is a next-generation proposed balloon/satellite mission that will be the first to target both MeV gamma-ray observations and antimatter-based indirect dark matter searches with a LArTPC (Liquid Argon Time Projection Chamber) detector. Astrophysical observations at MeV energies have not yet been well-explored due to the complexity and difficulties of the...
We revisit the acceleration of particles at the interface between a collimated laminar jet and the ambient medium. The contrast between standard diffusive scattering treatments and anomalous transport in synthetic field constructions is explored. A particular emphasis is placed on the necessity for physically consistent particle transport considerations. The temporal, spatial and spectral...
A High-Energy Particle Detector will be launched on board the CSES-02 satellite with the main purpose of deepening our comprehension of the Earth magnetosphere, investigating the Inner Van Allen belts and contributing to the understanding of sub-GeV cosmic rays.
HEPD-02 is composed of two segmented scintillator layers for the trigger, a silicon pixel tracker and a calorimeter. The detector is...
In extensive air showers induced by ultra-high energy (UHE) cosmic rays, secondary photons are expected to be produced at energies far above those accessible by other means. It has been shown that the decay of such photons, as possible in certain theories allowing the violation of Lorentz invariance, can lead to significant changes of the shower development. Based on observations of the...
This talk presents phenomenology related to the observation of high energy atmospheric neutrinos in the Deep Underground Neutrino Experiment (DUNE). DUNE is a next-generation long-baseline neutrino oscillation experiment designed to perform precision measurements of the neutrino parameters and study neutrino interactions. This program includes the construction of four 17 kT Far Detector (FD)...
On January 14, 2019, the most energetic photons ever observed from a gamma-ray burst were recorded by the Major Atmospheric Gamma Imaging Cherenkov (MAGIC) telescopes, detecting GRB 190114C at TeV energies. We used this unique observation to probe an energy dependence of the speed of light in vacuo for photons, as predicted by several quantum gravity models. From a set of conservative...
Gamma-Ray bursts, flaring active galactic nuclei and pulsars are distant and energetic astrophysical sources, detected up to tens of TeV with Imaging Atmospheric Cherenkov Telescopes (IACTs). Due to their high variability, they are the most suitable sources for energy-dependent time-delay searches related to Lorentz Invariance Violation (LIV) predicted by some Quantum Gravity (QG) models....
The detection of electromagnetic (EM) emission following the gravitational wave (GW) event GW170817 opened the era of multi-messenger astronomy with GWs and provided the first direct evidence that at least a fraction of binary neutron star (BNS) mergers are progenitors of short Gamma-Ray Bursts (GRBs). GRBs are also expected to emit very-high energy (VHE, > 100 GeV) photons, as proven by the...
The gamma-ray source 3HWC J1928+178, discovered by HAWC, is coincident with the 82 kyr pulsar PSR J1928+1746, located 4 kpc away. It has not been reported by any Imaging atmospheric Cherenkov Telescope (IACT), until the recent detection of emission from this region by HESS, using an analysis adapted to extended sources. No counterpart in GeV gamma-rays from Fermi-LAT data or in X-ray has been...
Extended gamma-ray halos around middle-aged pulsars, discovered at TeV energies from HAWC observations, are a new and potentially rich source class. The phenomenon is interpreted as the inverse-Compton scattering of ambient photons by electron/positron pairs accelerated by pulsars and their nebulae and confined in their vicinity. Physically, the dynamics of this pair confinement remains poorly...
We describe a future gamma-ray/cosmic-ray mission concept called the Advanced Particle-astrophysics Telescope (APT). The instrument combines a pair tracker and Compton telescope in a large monolithic design. By using scintillating fibers for the tracker and wavelength-shifting fibers to readout CsI detectors, the instrument could achieve more than an order-of-magnitude improvement in both...
The Compton Spectrometer and Imager (COSI) is a 0.2-5 MeV Compton telescope capable of imaging, spectroscopy, and polarimetry of astrophysical sources. Such capabilities are made possible by COSI's germanium cross-strip detectors, which provide high efficiency, high resolution spectroscopy and precise 3D positioning of photon interactions. Science goals for COSI include studies of 511 keV...
Crystal Eye is a new concept of all sky monitor for the observation of 10keV-30MeV cosmic photons exploiting a new detection technique, which foresees enhanced localization capability with respect to current instruments. This is now possible thanks to the use of new materials and sensors.
The proposed detection module is designed to be easily installed either on free flyer satellites or...
Since 2015, the direct detection of Gravitational Waves (GW) became possible with groundbased interferometers like LIGO and Virgo. GWs became the center of attention of the astronomical community and electromagnetic observatories took a particular interest in follow-up observations of such events. The main setback of these observations is the poor localization of GW events. In fact, GW...
We recently performed a population study of the HESS Galactic Plane Survey (HGPS)
considering the specific assumption that most of the bright TeV gamma-ray sources observed by HESS are powered by pulsar activity, such as PWNe or TeV halos.
In this paper, we discuss the implications of the TeV source population for the interpretation of Fermi-LAT data in the GeV domain.
We show that...
Relativistic jets are believed to be born magnetically dominated.
Very and ultra-high energy cosmic rays can be efficiently accelerated by magnetic reconnection in these sources. We here demonstrate this by means of three-dimensional relativistic magnetohydrodynamical (3D-RMHD) simulations, injecting thousands of initial low-energy particles in the transition region of the relativistic jet...
Using particle tracking in 3D relativistic magnetohydrodynamical simulations, we investigate the espresso mechanism, a one-shot reacceleration of galactic cosmic rays that may lead to the production of ultra-high-energy cosmic rays (UHECRs) in the relativistic jets of active galactic nuclei. In this work we also include UHECR diffusion due to small-scale magnetic fluctuations,...
Here we present the current technical design of the SPHERE project’s new detector. The SPHERE project is aimed at primary cosmic ray studies in the 1-1000 PeV energy range using reflected Cherenkov light. The concept of a drone-mounted detector with a photosensitive camera based on silicon photomultipliers is discussed. The combination of the reflected CL registration method with specific data...
An analysis of 7.5 years of data in the high-energy starting event sample has been recently published by the IceCube collaboration. The hottest spot in a search for neutrino sources was found far above the Galactic plane and is thus, at first sight, difficult to reconcile with a Galactic origin. In this work, we calculate the cosmic ray (CR) density around nearby, young supernova remnants,...
Cosmic rays (CRs) are responsible for a tight correlation between the star formation rate (SFR) and the radio and gamma-ray luminosity observed in star-forming galaxies (SFGs). This correlation can possibly be explained by a linear scaling between the SFR and the number of CR acceleration sites, such as supernova remnants, coupled to the dependence of particle escape with galaxy properties....
We demonstrate that global observations of high-energy cosmic rays contribute to understanding unique characteristics of a large-scale magnetic flux rope (MFR) causing a magnetic storm in August 2018. Following a weak interplanetary shock on 25 August 2018, a MFR caused an unexpectedly large geomagnetic storm. It is likely that this event became geoeffective because the MFR was accompanied by...
Adaptive filtering belongs to the realm of learning algorithms, so widely used in our daily life when we hear about machine learning, artificial intelligence, pattern recognition, etc. It is formally defined as a self-designing device with time-varying parameters that are adjusted recursively in accordance with the input data.
The trigger mechanism is known to be a central task in radio...
The GRAPES-3 experiment operated in Ooty, India is designed to record the electron and muon components of extensive air showers (EAS). The signal processing and DAQ system have been going through systematic upgrades. Currently, GRAPES-3 is operating 400 plastic scintillators of size 1 m$^2$ spread over an area of 25000 m$^2$ and 3712 proportional counters (PRCs) divided into 16 modules with a...
The nitrogen laser calibration system for the Wide Field of View Cherenkov Telescope Array (WFCTA) is one of the most important components of the Large High Altitude Air Shower Observatory (LHAASO). This calibration system is composed of three parts, including a high-precision 3D lifting and rotating platform (HiRoP), a nitrogen laser and the wide field of view Cherenkov telescope prototypes....
Since 2015 the Pierre Auger Observatory has been undergoing an important upgrade. It consists of the addition of Scintillator Surface Detectors (SSD) on top of the existing Water-Cherenkov Detectors (WCDs), as well as Underground Muon Detectors (UMD), a small Photo-Multiplier Tube (sPMT) inside the WCDs and a Radio Detector antenna array, at each of the 1660 surface detector stations. To...
The Wide Field of View Cherenkov Telescope Array (WFCTA) of Large High Altitude Air Shower Observatory(LHAASO) is designed to measure the extensive air showers created by cosmic rays from ~30 TeV to several EeV. In order to employ an end-to-end calibration method for WFCTA, four laser lidar systems have been developed successfully and installed at the LHAASO. Two N2 lasers with the 337.1 nm...
The leading explanation of the $\textit{Fermi}$ Galactic center $\gamma$-ray excess is the extended emission from a unresolved population of millisecond pulsars (MSPs) in the Galactic bulge. Such a population would, along with the prompt $\gamma$ rays, also inject large quantities of electrons/positrons ($e^\pm$) into the interstellar medium. These $e^\pm$ could potentially inverse-Compton...
The measurement of diffuse gamma-ray emission could provide new insights into the propagation and acceleration of Galactic cosmic rays, the origin of neutrinos observed by IceCube, and the nature of dark matter. KM2A array in LHAASO is devoted to the detection of extensive air showers for gamma-ray astrophysics. Thanks to its large effective area and the good gamma/hadron separation, KM2A...
Gamma-ray bursts (GRBs) are among the most luminous sources in the universe. The nature of their emission at TeV energies is one of the most relevant open issues related to these events. Due to its large field of view and duty cycle, HAWC is ideal for studying transient phenomena with gamma-ray emission and probing different model assumptions. In this work, we search for gamma-ray emission in...
Recently, there has been an increased interest in small-scale EAS experiments designed to satisfy young people's scientific curiosity and develop their interest in science. It is worth noting that networking these arrays creates opportunities to pose and solve serious physical problems.
The particle flux on the ground, due to the steep cosmic ray spectrum, is dominated by particles from small...
Neutrinos can escape dense environments, otherwise opaque to photons, and travel cosmic distances unscathed by background radiation or magnetic fields. While ideal cosmic messengers, they present a unique opportunity to test physics beyond the Standard Model, especially dark matter. Moreover, there is a distinct possibility that the neutrino sector is the principal portal through which the...
We show how the LHAASO experiment, located in the province of Sichuan (China), can provide a unique opportunity to test new heavy candidates of Particle Dark Matter (DM) beyond the currently explored regimes, namely ~1 PeV and higher. Such scenarios are motivated by several DM models featuring different mechanisms for DM production in the early Universe. In particular, PeV mass DM can decay...
Fourier transform of a signal f computes the correlation between f and the (frequency ranged) orthogonal basis of sines. Although this brings relevant information, the limitation is clear when we want to detect singularities in the signal. The uncertainty principle states that the energy spread of a function and its Fourier transform cannot be simultaneously arbitrarily small. As the...
At the IceCube Neutrino Observatory a Surface Array Enhancement is planned, consisting of 32 hybrid stations, placed within the current IceTop footprint. This surface enhancement will considerably increase the detection sensitivity to cosmic rays in the 100 TeV to 1 EeV primary energy range, measure the effects of snow accumulation on the existing IceTop tanks and serve as R&D for the possible...
CRAFFT is an atmospheric fluorescence telescope with wide viewing pixels for Ultra-High Energy Cosmic Rays next-generation observation facility. We have builded the automatic observation system (for the fluorescence detector) in order to expand detection area of the next generation observatory by the telescope with the fluorescence technique. In Japan, we made a testing machine that reproduces...
We develop a drone-borne aerial calibration pulser system for radio observatories for air-showers induced by ultra-high energy (UHE) cosmic rays (CRs) and cosmic neutrinos (CNs). The system is designed to provide a highly practical method for system calibration which transmits high power impulsive radio signals from various locations. We use a solid-state impulse generator and a wide-band...
Air-shower radio array operate in low signal-to-noise ratio conditions, which complicates the autonomous measurement of air-shower signals without using an external trigger from optical or scintillator detectors. A simple threshold trigger for radio can be efficiently applied only in radio-quiet conditions, because for other cases this trigger detects a high fraction of noise pulses. In the...
The method of “weighting fields” gives an efficient way to compute the signal produced in a detector by a passing charged particle. Originally based on (quasi-)electrostatic approximations, this so called Ramo-Shockley theorem is heavily used to calculate signals in detectors based on ionisation, like gas detectors or silicon sensors. I will present an extension of the method to encapsulate...
Extensive air showers in astroparticle physics experiments are commonly simulated using CORSIKA. The electromagnetic shower component has been treated using EGS4 in the Fortran 77-based versions, which have been developed in the last thirty years. Currently, CORSIKA is being restructured and rewritten in C++, leading to the new version CORSIKA 8. In this process, the electromagnetic component...
The Extreme Universe Space Observatory - Super Pressure Balloon (EUSO-SPB2) mission will fly two custom telescopes that feature Schmidt optics to measure Cherenkov- and fluorescence-emission from extensive air-showers at the PeV and EeV-scale. Both telescopes have 1-meter diameter apertures and UV/UV-visible sensitivity. The Cherenkov telescope uses a bifocal mirror segment alignment, to...
Starburst galaxies (SBGs) and more generally starforming galaxies represent a class of galaxies with a high star formation rate (10-100 Mo/year). Despite their low luminosity, they can be considered as guaranteed “factories” of high energy neutrinos, being “reservoirs” of accelerated cosmic rays and hosting a high density target gas in their central region. In this contribution, the...
Galactic winds are one of the most spectacular phenomena we observe in the Universe.
They are common in active galaxies, and can be powered either by stellar feedback typical of star forming galaxies or by active galactic nuclei (AGN).
These winds have a bubble structure characterized by an external forward shock expanding in the circumgalactic medium and an internal reverse shock...
The recent detection of a very high energy (VHE) emission from Gamma-Ray Bursts (GRBs) above 100 GeV performed by the MAGIC and H.E.S.S. collaborations, has represented a significant, long-awaited result for the VHE astrophysics community. Although these results' scientific impact has not yet been fully exploited, the possibility to detect VHE gamma-ray signals from GRBs has always been...
A newly redesigned version of a mini-neutron monitor (NM), with updated and more sensitive electronics, was installed on the South African Antarctic research vessel, the SA Agulhas II, at the end of 2019. The 2019/2020 relief voyage to the SANAE (South African Antarctic base) research station was used to test the performance of the instrument. Results indicate that the new design, featuring a...
We have developed the "Opt-copter" as a calibration device for fluorescence detectors (FDs). The Opt-copter is a UAV equipped with a light source. The Opt-copter is also equipped with a RTK-GPS of 10 cm position measurement resolution, which allows it to fly within the FD's field of view(FOV) while accurately measuring the position of the light source. This allows us to measure the optical...
We present the observation of an anomalous increment of the galactic cosmic ray (GCR) flux observed by the HAWC array during October 2016. We propose that an anisotropy of the GCR flux caused by a magnetic flux rope (MFR) i. e., by the helical magnetic field of an interplanetary coronal mass ejection observed at 1 AU at the same time, was responsible for the GCR increment.
We computed the...
In analyzing the anisotropy of galactic cosmic rays below 1 TeV, graphs
with time as the horizontal axis frequently represent the cosmic ray
intensity variations. Therefore, the anisotropy is often misinterpreted
as a "temporal variation," even though essentially regarded as a
"spatial distribution."
This paper presents a high-resolution two-dimensional map of the
solar-time anisotropy...
I will outline the science opportunities in the areas of searches for dark matter and new physics offered by a proposed future MeV gamma-ray telescope, the Galactic Explorer with a Coded Aperture Mask Compton Telescope (GECCO). I will point out that such an instrument would play a critical role in opening up a discovery window for particle dark matter with mass in the MeV or sub-MeV range, in...
An anomalous flux of neutrinos produced in hypothetical annihilations or decays of dark matter inside a source would produce a signal observable with neutrino telescopes. As suggested by observations, a conspicuous amount of dark matter is believed to accumulate in the Centre of our Galaxy, which is in neat visibility for the Mediterranean underwater telescopes ANTARES and KM3NeT. Searches...
Dark matter remains one of the most important open problems in particle physics and cosmology. Weakly interacting massive particles (WIMPs) appear as an appealing solution, providing the right relic density with a cross-section at the electroweak scale, however, no WIMP signals were observed until now. Secluded models are good alternatives to the standard ones. In this case, instead of a...
Dark matter (DM) in cosmic structures is expected to produce signals originating from its particle physics nature, among which the electromagnetic emission represents a relevant opportunity. One of the major candidates for DM are weak-scale particles, however no convincing signal of them has been observed so far. For this reason, alternative candidates are getting increasing attention, notably...
Mini-EUSO is a new space-based experiment designed primarily to observe showers that develop in atmosphere due to the interaction between molecular nitrogen and Ultra High Energy Cosmic particles (above 10 ZeV) crossing by. It belongs to the JEM-EUSO program, which includes
several past experiments all devoted to develop new larger size satellite detectors like K-EUSO and POEMMA for future...
Clarifying the origin and nature of ultra-high-energy cosmic rays (UHECRs) is of the uppermost importance in the astroparticle physics. The Fluorescence detector Array of Single-pixel Telescopes (FAST) is a design for a next-generation ground-based UHECR observatory, addressing the requirements for a large-area, low-cost detector suitable for detecting the properties of UHECRs with an...
It has been established that Gamma-Ray Bursts (GRB) can produce Very High Energy radiation (VHE, E > 100 GeV), opening a new window on the investigation of particle acceleration and radiation properties in the most energetic domain. We expect that next-generation instruments, such as the Cherenkov Telescope Array (CTA), will mark a huge improvement in their observation. However, constraints on...
The excess of gamma rays in the data measured by the Fermi Large Area Telescope from the Galactic center region is one of the most intriguing mysteries in Astroparticle Physics. This Galactic center excess (GCE), has been measured with respect to different interstellar emission models, source catalogs, data selections and techniques. Although several proposed interpretations have appeared in...
Magnetic activity on the sun influences the flux of galactic cosmic rays at Earth in the process known as solar modulation. While most pronounced at 1 GeV and below, it also operates at much higher energy, still exhibiting solar magnetic polarity dependence. An observational gap exists between approximately 18 GeV (the highest geomagnetic cutoff) neutron monitor data and greater than 50 GeV...
The new coordinate-tracking detector was developed in the Experimental complex NEVOD, MEPhI for the study of near-vertical extensive air showers. The installation consists of two planes of drift chambers, 7 chambers in each, and has an effective area of 13 m^2. The registration system of the new detector gets trigger from scintillator counters and uses the TDC that has been specially designed...
An updated yield function (YF) of a standard NM64 neutron monitor (NM) is computed and extended to different atmospheric depths from sea level to 500 g/cm$^2$ ($\sim$5.7 km altitude) and is presented as lookup tables and a full parametrization. NM YF was computed using the PLANETOCOSMICS simulation tool based on the GEANT4 package, applying the NRLMSISE-00 atmospheric model. The yield function...
We will report recent progress on the on-going NuSTAR observation campaign of 8 TeV-detected pulsar wind nebulae (PWNe). This campaign (to be completed by June 2021) constitutes a major part of our NuSTAR study of some of the most energetic TeV sources in our galaxy detected by VERITAS and HAWC. NuSTAR is the only focusing X-ray telescope operating above 10 keV in space with sub-arcminute...
Mini-EUSO is the first detector of the JEM-EUSO program deployed on the International Space Station (ISS). It is a wide field of view telescope currently operating from a nadir-facing UV-transparent window in the Russian Zvezda module on the ISS. It is based on an array of Multi-Anode Photomultipliers Tubes (MAPMTs) working in photon counting mode with a microsecond time resolution. Among the...
We investigate the process of particle acceleration at the termination shock that develops in the bubble excavated by star clusters’ winds in the interstellar medium. We develop a theory of diffusive shock acceleration at such shock and we find that the maximum energy may reach the PeV region for very powerful clusters.
We show how the maximum energy is limited by two different processes: the...
The H.E.S.S. Galactic Plane Survey has detected very-high-energy (VHE) gamma-ray emission from 78 sources in the Milky Way. These sources belong to different object classes (pulsar wind nebulae, supernova remnants or binary systems) and some of these sources remain unidentified. The gamma-ray emission of these objects may be of leptonic or hadronic origin and gamma-ray observations alone...
A observatory for the next generation of ultra-high energy cosmic rays (UHECRs) should be expanded for clarifying the origin and nature of UHECRs. In order to realize a huge UHECR observatory, we are developing Cosmic Ray Air Fluorescence Fresnel lens Telescope (CRAFFT), which is a low-cost fluorescence telescope.We tested a performance of prototype CRAFFT at Telescope Array (TA) site, and...
Discrimination of secondary particles produced in extensive air showers is needed to study the composition of primary cosmic rays. High speed data acquisition and the increase in resources in modern FPGAs with the addition of a microprocessor in System-on-Chip (SoC) technologies allow to implement complex algorithms for digital signal analysis. Pulse Shape Discrimination (PSD) can be carried...
Radio detection of air showers produced by ultra-high energy cosmic rays is a cost-effective technique for the next generation of sparse arrays. The performance of this technique strongly depends on the environmental background, which has different constituents, namely anthropogenic radio frequency interferences, synchrotron galactic radiation and others. These components have recognizable...
Detecting and studying galactic gamma-ray sources emitting very-high energy photons sheds light on the acceleration and propagation of cosmic rays presumably created in these sources. Currently, there are few sources emitting photons with energies exceeding 100 TeV. In this work we revisit the unidentified source MGRO J1908+063, initially detected by Milagro, using an updated H.E.S.S. dataset...
ROOT-Based Simulator for Ray Tracing (ROBAST) is an open source library designed to simulate complex optical systems used in Cherenkov and fluorescence telescopes. It has been used for the Cherenkov Telescope Array (CTA) more than 10 years to simulate hexagonal light concentrators and parabolic, Davies–Cotton, and Schwarzschild–Couder optical systems. In addition to CTA, ROBAST is also used in...
During a core-collapse supernova (SN), axion-like particles (ALPs) could be produced through the Primakoff process and subsequently convert into gamma rays in the magnetic field of the Milky Way. Using a sample of well studied extragalactic SNe at optical wavelengths, we estimate the time of the core collapse and search for a coincident gamma-ray burst with the Fermi Large Area Telescope...
ANTARES is an underwater neutrino detector in the Mediterranean Sea. Its location, reconstruction accuracy for all-flavor neutrino interactions, and low energy threshold, make it the most sensitive neutrino observatory for searches below 100 TeV over large parts of the sky. The HAWC experiment is a water Cherenkov gamma-ray detector located in Mexico. Thanks to its large field of view it is an...
We present the first search for dark matter (DM) spectral lines in the Galactic centre (GC) region with the MAGIC telescopes. The MAGIC telescopes, located on the Canary island of La Palma (Spain), are sensitive to gamma rays in the energy range from 50 GeV to 50 TeV. MAGIC has performed indirect DM searches with various astrophysical targets, such as dwarf spheroidal galaxies and clusters of...
The observation of very high energy ($\rm VHE: >100GeV$) photon from $\gamma$-ray bursts (GRBs) can advance our understanding of their radiation mechanism, the evolution of host-galaxies, violations of Lorentz invariance, extragalactic background light, and intergalactic magnetic field. Recently the measurements on VHE emission from afterglow phase have blossomed and borne fruit while results...
Despite mounting evidence that dark matter (DM) exists in the Universe, its fundamental nature remains unknown. We present sensitivity estimates to detect DM particles with a future very-high-energy (≳ TeV) wide field-of-view gamma-ray observatory in the Southern Hemisphere, currently in its research and development phase under the name Southern Wide field-of-view Gamma-ray Observatory (SWGO)....
High-energy gamma rays are promising tools to constrain or reveal the nature of dark matter, in particular Weakly Interacting Massive Particles. Being well into its pre-construction phase, the Cherenkov Telescope Array (CTA) will soon probe the sky in the 20 GeV - 300 TeV energy range. Thanks to its improved energy and angular resolutions as well as significantly larger effective area when...
We are observing extensive air showers using Tibet-III air shower array located at 4300 m above sea level. Such situation at high altitude enables us to measure the chemical composition of cosmic rays above several tens TeV by analyzing the shower profiles. A water-Cherenkov Muon Detector array (MD) was added in 2014 to measure the muon intensity of air showers and performance of particle...
On 14th January 2019, the MAGIC collaboration achieved the first significant detection at TeV energies of a gamma-ray burst (GRB), namely GRB 190114C. This observation sets the first experimental proof of very high energy (VHE, >~100 GeV) gamma-ray emission in GRBs, after more than 50 years from the first GRB detection and many searches with Cherenkov telescopes in the last decades. The data...
Previously, the non-thermal emission from galaxies has only been modeled with single-zone models which is insufficient to explain a multitude of new, spatially resolved multi-messenger data of cosmic ray (CR) spectra, at gamma-rays and in the radio. Instead, we perform high-resolution magneto-hydrodynamic simulations of galaxies using the moving mesh code AREPO with self-consistent CR physics....
Originally Micro-Pattern Gas Detectors (MPGDs), a type of gaseous ionization detector, were developed for high energy physics. However applications have expanded to astrophysics, neutrino physics, neutron detection, and medical imaging. Over the past 20 years this led to the development of novel MPGD devices: the Micro-Strip Gas Chamber, Gas Electron Multiplier (GEM), Micromegas and many...
Since February 2018, simultaneous observation of cosmic ray (CR) muon and neutron is continued. The operation is quite stable and its duty cycle is higher than 94%. These detectors are showing their usefulness by responding to, for example, a peculiar CME event in August 2018. There is another interesting event in September 2019. A Sudden Stratospheric Warming (SSW) was observed and muon...
The coexistence of powerful accelerators of cosmic rays with intense background radiation fields creates unique conditions in astrophysical sources, where the Ultra-High-Energy-Cosmic-Rays (UHECRs) interactions could take place copiously and produce several secondary particles.
In particular, such phenomena could explain the features observed in the UHECR spectrum measurements.
We...
The simulation program CORSIKA is the leading tool for the research in air shower physics for over 30 years. It is recently undergoing a huge development effort, driven by the migration from FORTRAN77 to modern C++17, in order to achieve the highest performance and functionality, deploying parallelism and engaging different platforms like GPU and many-core CPU, using efficient and...
Muon hodoscope URAGAN (MEPhI, Moscow) with an area of 45 sq. m is capable of real time detection of the tracks of all muons arriving from the upper celestial hemisphere with a high spatial and angular accuracy (1 cm and 1 degree, respectively). The spatial-angular distribution of the muons flux, measured by means of the URAGAN hodoscope for a certain period of time (1 min.) and expressed in...
To research the “knee” region of cosmic ray energy spectrum, we should clearly discriminate components of cosmic rays at the knee. EN-detectors (Electron-Neutron Detector) can detect both electrons and thermal neutrons generated in ground by EAS hadrons, so that the electron-neutron detector array (ENDA) can improve capability of primary components separation and energy measurement of LHAASO...
The measurement of thermal neutrons generated by cosmic ray extensive air showers (EAS) on the Earth’s surface provides a new method for studying the composition and energy of cosmic rays with energy in the so-called “knee” region. The electron-neutron detector (EN-detector) utilizes a new type scintillator based on a compound alloy of ZnS(Ag) and B2O3 with natural boron. Totally 64...
The recent discovery of a teraelectronvolt (TeV) component in a few long GRBs and possibly in the short GRB 160821B, deepened the insight on GRB physics and opened the new TeV window in their observation, and in the study of the multi-messenger counterparts, e.g. gravitational waves. The exact nature of the TeV component and the details on the implications on the emission region need to be...
The Latin American Giant Observatory (LAGO) consists of a network of small water Cherenkov detectors (WCD) located at different sites in Latin America. It is a large aperture observatory sensitive to high energy gamma rays and due to its high duty cycle, LAGO constitutes a facility to detect transient events from the ground. Gamma Ray Bursts (GRBs) are of the brightest transients detected,...
The TeV gamma-ray source MGRO J1908+06 is one of the highest-energy sources known, with observed emission by the High Altitude Water Cherenkov (HAWC) Observatory extending well past 100 TeV. The source exhibits both energy-dependent morphology and a spatially-dependent spectral index. The emission is likely to be dominantly leptonic, and associated with the radio-quiet PSR J1907+0602. However,...
One of the crucial detector systems of the Pierre Auger Observatory is the fluorescence detector composed of 27 large-aperture wide-angle Schmidt telescopes.
In the past, these telescopes were absolutely calibrated by illuminating the whole aperture with a uniform large-diameter light source.
This absolute calibration was performed roughly once every three years, while a relative calibration...
The atmospheric quality plays an import role in the air shower observation by the Wide Field of View Cherenkov Telescope Array (WFCTA) of LHAASO. A YAG imaging lidar system was developed to continuously monitor the calorimetric information. The accuracy of atmospheric monitoring is dependent on the pulse energy, the YAG laser’s beam parameters and the angular repeatability of a High-precision...
The ASTRI Mini-Array (ASTRI-MA) is an INAF project to construct and operate an array of Imaging Atmospheric Cherenkov Telescopes to study gamma-ray sources in the TeV range. The ASTRI-MA will consist of nine double-mirror telescopes that will be installed at the Teide Astronomical Observatory, Instituto de Astrofísica de Canarias, in Tenerife (Spain). Its main scientific goal is to perform...
The network of MRPC (Multi-gap Resistive Plate Chambers) telescopes of the Extreme Energy Events experiment (EEE) was designed to study very high energy cosmic rays mainly through the detection of secondary cosmic muons in the hadronic shower. To better understand and predict the behavior of such events, a GEANT4-based simulation framework that well reproduces the response of individual...
Tunka-Rex (Tunka Radio Extension) was a detector for ultra-high energy cosmic rays measuring radio emission for air showers in the frequency band of 30-80 MHz, operating in 2010s. It provided an experimental proof that sparse radio arrays can be a cost-effective technique to measure the depth of shower maximum with resolutions competitive to optical detectors. After the decommissioning of...
The MAGIC telescopes has developed a dedicated observational strategy to repoint rapidly towards gamma-ray bursts (GRB). In this contribution we present the information extracted from the large sample of the GRBs observed but not detected by MAGIC from 2013 to 2019 aiming to shed light on the reasons behind those non-detections.The same strategy led to the successful detection of two GRBs at...
Gamma-ray bursts (GRBs) are the most energetic phenomena in the universe. Many aspects of GRB physics are still under debate, such as the origin of their gamma-ray emission above the GeV energy range.
In 2019, MAGIC detected TeV gamma rays from the long GRB 190114C, whose emission can be well explained by synchrotron-self Compton emission by relativistic electrons. However, it is still...
