Dr
Monica Vazquez Acosta
(Instituto de Astrofisica de Canarias)
27/08/2018, 14:00
Indirect searches for dark matter with the ground-based MAGIC telescopes will be reviewed. Different targets with a large expected dark matter content, such as galaxy clusters and dwarf satellite galaxies, allow to constrain dark-matter annihilation/decay processes up to the TeV mass scale. Latest results from deep observations of the galaxy cluster Perseus and the dwarf spheroidal Ursa Major...
Ms
Stefania Vitillo
(University of Geneva)
27/08/2018, 14:00
The Dark Matter Particle Explorer (DAMPE) is a high energy astroparticle satellite launched on the 17th December 2015 into a sun-synchronous orbit at an altitude of 500 km. The DAMPE detector consists of a double layer of Plastic Scintillator strips Detector (PSD), followed by a Silicon-tungsten TracKer-converter (STK), a Bismuth Germanium Oxide electromagnetic calorimeter (BGO) and a NeUtron...
Joshua Wood
(University of Wisconsin, Madison)
27/08/2018, 14:00
The IceCube Neutrino Observatory studies a wide range of phenomena including neutrino astronomy, dark matter searches, neutrino oscillations, and cosmic ray physics using a cubic kilometer of instrumented ice at the South Pole. Recently, IceCube reported evidence for the first identified source of the high energy astrophysical neutrino flux. This represents a major milestone towards...
Dr
Li.Qiao Yin
(IHEP, CAS)
27/08/2018, 14:17
Large High Altitude Air Shower Observation (LHAASO), located in Daocheng Haizishan, 4300m a.s.l., Sichuan Province, Chain, is under construction now and is expected to be completely operated by 2021. One of the main science objects of LHAASO is to precisely measure the cosmic rays energy spectrum of individual components from 1014 eV to 1018 eV. LHAASO is consist of four types of detectors:...
Mr
Nathan Kelley-Hoskins
(DESY)
27/08/2018, 14:20
VERITAS is an imaging atmospheric Cherenkov observatory that is sensitive to gamma rays in the energy range between 85 GeV and > 30 TeV. VERITAS observations allow for the study of a wide variety of physics, including energetic environments inside and outside our galaxy, searches for dark matter, and a number of topics in astroparticle physics. We present an update on indirect dark matter...
Mr
Andrii Petrashyk
(Columbia University)
27/08/2018, 14:34
The origin of very high energy (VHE) cosmic rays is one of the oldest and deepest puzzles of astrophysics. Understanding particle production and acceleration in astrophysical sources, and the mechanisms of propagation of cosmic rays through the interstellar medium is paramount to solving this fundamental problem. Cosmic rays produced in nearby accelerators can be observed directly through...
Dr
Imen Al Samarai
(UNIGE)
27/08/2018, 14:35
A high-energy neutrino event detected by IceCube on 22 September 2017 was coincident in direction and time with a gamma-ray flare from the blazar TXS 0506+056. Prompted by this encounter, 10 years of IceCube neutrino data were searched for additional, independent neutrino emission from the position of the blazar. Two methods were applied to search for an excess of neutrino events in the...
Pat Harding
(Los Alamos National Laboratory)
27/08/2018, 14:40
TeV photons provide unique tests of fundamental physics phenomena, such as dark matter annihilation and decay. The High Altitude Water Cherenkov (HAWC) Observatory is an extensive air shower array sensitive to gamma rays from 500 GeV - 100 TeV. HAWC is capable of performing indirect dark matter searches in a mass range that is inaccessible to most other experiments. The HAWC wide field-of-view...
Prof.
Markus Boettcher
(North-West University)
27/08/2018, 14:50
Recently, the IceCube Neutrino Observatory has alerted the astrophysical
community about the detection of a very energetic neutrino event (called
IceCube-170922A). Upon this alert, the Large Area Telescope (LAT) on
board the Fermi Gamma-ray Space Telescope reported enhanced gamma-ray
emission from BL Lac object TXS 0506+05, compatible with the direction
of IceCube-170922A. The fact that...
Dr
Kohei Hayashi
(Institute for Cosmic Ray Research, The University of Tokyo)
27/08/2018, 15:00
The galactic dwarf spheroidal (dSph) galaxies are the promising targets for the dark matter indirect searches for particle dark matter. To place robust constraints on candidate dark matter particles, understanding the dark matter distribution of these systems is of substantial importance.
However, various non-negligible systematic uncertainties complicate the estimate of the J-factors...
Dr
Yves Gallant
(LUPM, CNRS/IN2P3, U. Montpellier)
27/08/2018, 15:00
The H.E.S.S. Galactic Plane Survey (HGPS) provides the most comprehensive view to date of the inner Milky Way in TeV gamma-rays. Of the sources detected, 40% can be firmly identified, mostly as pulsar wind nebulae (PWNe) or supernova remnants (SNRs). The uniform analysis of the HGPS allows systematic studies of the populations of these two classes of TeV-emitting objects.
The...
Mr
Theo Glauch
(Technical University of Munich)
27/08/2018, 15:05
On September 22, 2017, the IceCube Neutrino Observatory has observed for the first time ever an extremely high-energy neutrino IceCube-170922 spatially and temporally consistent with a gamma-ray flaring blazar, TXS 0506+056. The region around the event is, however, crowded with several other thermal and non-thermal sources. In order to get a clear picture of the possible neutrino counterparts...
Mr
Antony Escudie
(Subatech - IMT Atlantique - Nantes - France)
27/08/2018, 15:08
Over the years, significant efforts have been devoted to the understanding of the radio emission of extensive air shower (EAS) in the range [20-80] MHz but, despite some studies led until the nineties, the [1-10] MHz band has remained unused for nearly 30 years. At that time it has been measured by some pioneering experiments but also suggested by theoretical calculations that EAS could...
Pearl Sandick
(University of Utah)
27/08/2018, 15:15
Dwarf spheroidal galaxies are are exceptionally clean targets for searches for gamma rays from dark matter annihilation. Here, I will discuss a general, model-independent formalism for determining bounds on the production of photons from dark matter annihilation in dwarf spheroidal galaxies. This formalism is applicable to any set of assumptions about dark matter particle physics or...
Dr
Kaya Mori
(Columbia University)
27/08/2018, 15:15
We present follow-up X-ray and gamma-ray observations of two unidentified Galactic HAWC sources, 2HWC J1928+177 and 2HWC J1953+294, with the NuSTAR and VERITAS observatories. VERITAS gamma-ray observations of 2HWC J1928+177 resulted in upper limits, while a follow-up NuSTAR X-ray observation detected a variable X-ray point source with a bright IR counterpart. The HAWC source could be powered...
Stijn Buitink
(Vrije Universiteit Brussel)
27/08/2018, 15:25
Air showers can be detected by the short radio pulses they emit. The LOFAR radio telescope contains a dense core region where 384 antennas are located within a circle of 320 m diameter. Here, the properties of radio emission from air showers have been measured in unprecedented detail. The complicated radiation patterns on the ground have been shown to agree with modern theory, including the...
Dr
Ekrem Oguzhan Angüner
(CPPM)
27/08/2018, 15:30
HESS J1826$-$130 is an unidentified very-high-energy (VHE, E>0.1 TeV) gamma-ray source discovered by H.E.S.S. along the Galactic plane. The analysis of 215-hour H.E.S.S. data has revealed a steady TeV source with an extension of 0.21°. The source spectrum can be well described with a power-law function, showing a very hard spectral index of $\Gamma$ = 1.8 and an exponential cut-off at ~15 TeV....
Mr
Nicholas Rodd
(Massachusetts Institute of Technology)
27/08/2018, 15:30
Cherenkov telescopes such as HESS, VERITAS, and CTA, represent one of the most promising avenues to detect popular dark matter candidates like the wino, higgsino, and minimal dark matter. Yet theoretical predictions for the annihilation rate and spectrum of photons produced in such models is a notoriously difficult multi-scale problem, sensitive to the dark matter mass, electroweak scale, and...
Rafael Alves Batista
(University of São Paulo)
27/08/2018, 16:15
In the last decades significant progress has been made towards understanding the origin and nature of ultra-high-energy cosmic rays (UHECRs). However, their sources and composition still remain largely unknown. To interpret the data and find the elusive sources of UHECRs, it is important to understand how cosmic rays propagate in the universe. This is not a trivial task, given our limited...
Riccardo Rando
(University of Padova and INFN)
27/08/2018, 16:15
In recent years several space-based instruments have probed the sky in hard X rays (E∼10–100 keV: NuSTAR, Swift, INTEGRAL) and in gamma rays (E∼0.1-1000 GeV: Fermi-LAT, AGILE) with considerable scientific return. On the other hand, the challenging energy band between these regimes has remained mostly unexplored since COMPTEL on CGRO (1991-2000). I will review the proposals for future...
Summer Blot
(DESY Zeuthen)
27/08/2018, 16:15
Since its discovery of the astrophysical neutrino flux, the IceCube
Neutrino Observatory has continued to provide invaluable knowledge about
both potential neutrino sources and neutrino properties at the GeV-PeV
scale through its detection of neutrino interactions via Cherenkov
radiation in the deep South Pole ice. In addition, IceCube is a strong
partner in the field of...
Shin'ichiro Ando
(University of Amsterdam)
27/08/2018, 16:15
We study evolution of dark matter substructures, especially how they lose the mass and change density profile after they fall in gravitational potential of larger host halos. We develop an analytical prescription that models the subhalo mass evolution and calibrate it to results of N-body numerical simulations of various scales from very small (Earth size) to large (galaxies to clusters)...
Mr
Hiroki Yoneda
(University of Tokyo)
27/08/2018, 16:35
Now we are in the era of multi-messenger astronomy including neutrinos and gravitational waves.
However, the observational window for gamma rays between 100 keV to a few tens of MeV is still closed.
This energy band can bring a key information on astrophysical phenomena such as the nuclear decaying gamma-ray lines from stellar explosions, e$^-$e$^+$ annihilation line, MeV dark matter and so...
Mr
Austin Schneider
(University of Wisconsin Madison)
27/08/2018, 16:35
The IceCube neutrino observatory has firmly established the existence of an astrophysical high-energy neutrino component. This discovery was made using the high energy starting events sample (HESE), which uses a veto to significantly reduce atmospheric background. In this talk I will present the latest astrophysical neutrino flux measurement using seven years of HESE. This latest iteration of...
Dr
Monica Vazquez Acosta
(Instituto de Astrofisica de Canarias)
27/08/2018, 16:35
A measurement of the Extragalactic Background Light (EBL) from a combined likelihood analysis of blazar spectra detected by the MAGIC Telescopes is presented. EBL is the optical-infrared diffuse background light accumulated during the history of the Universe, directly emitted (mostly) by stars or reprocessed by dust, providing unique information about the history of galaxy formation. The low...
Dr
Ranjan Laha
(Johannes Gutenberg University Mainz)
27/08/2018, 16:45
We propose a new method to search for axion-like particles (ALPs) based on the gamma-rays produced concomitant with high-energy astrophysical neutrinos. The existence of high-energy neutrinos implies production of gamma-rays in the same sources. Photons can convert into ALPs in the sources' magnetic fields, and will travel as ALPs through extragalactic space. Back-conversion in the Milky Way's...
Dr
Andrey Timokhin
(NASA/GSFC)
27/08/2018, 16:50
We present the Advanced Energetic Pair Telescope (AdEPT) which is being developed as a future NASA/GSFC MIDEX mission to perform high-sensitivity medium-energy (5–200 MeV) astronomy and revolutionary gamma-ray polarization measurements. The enabling technology for AdEPT is a large volume gaseous time projection chamber with high spatial resolution 2-dimentional readout. The accurate...
Juliana Stachurska
(DESY Zeuthen)
27/08/2018, 16:50
The IceCube Neutrino Observatory at the South Pole detects Cherenkov light from charged particles produced in neutrino interactions. At the highest energies, the neutrino flux is of cosmic origin, but its astrophysical sources are yet unknown. A measurement of the flavor ratio on Earth can provide important constraints on sources and production mechanisms. In this talk we present the...
Dr
Jacek Niemiec
(Institute of Nuclear Physics Polish Academy of Sciences)
27/08/2018, 16:55
Collisionless shocks are found in a number of astrophysical objects, ranging in size from the Earth's bow shock through solar flares, termination shock of the solar wind, supernova remnant shocks, and merger shocks in galaxy clusters. In the latter case, low Mach number (Ms << 10) shocks are found propagating in a high beta (β > 1) plasmas, where β is the ratio of thermal to magnetic pressure....
Mr
Galo Gallardo Romero
(DESY)
27/08/2018, 17:00
High energy γ-ray photons emitted by astrophysical sources are absorbed by pair production with the diffuse extragalactic background light (EBL), which results in a decrease of the transparency of the universe to γ rays. Multiple extensions of the Standard Model predict the existence of axion-like particles (ALPs), a new type of pseudoscalar particles that can couple to photons in the presence...
Mr
Cosimo Nigro
(DESY Zeuthen)
27/08/2018, 17:05
Analysis and combination of data from different gamma-ray instruments involves the use of collaboration proprietary software and case-by-case methods.
By defining a common open format for high-level gamma-ray data (containing event lists and instrument response functions, using the FITS standard) we allow multi-instrument analysis within the context of open-source software.
This...
Ruth Poettgen
(Lund University)
27/08/2018, 17:15
The origin and observed abundance of Dark Matter can be explained elegantly by the thermal freeze-out mechanism, leading to a preferred mass range for Dark Matter particles in the ~MeV-TeV region. The GeV-TeV mass range is being explored intensively by a variety of experiments searching for Weakly Interacting Massive Particles. The sub-GeV region, however, in which the masses of the building...
Dr
Henrike Fleischhack
(Michigan Tech)
27/08/2018, 17:20
The High Altitude Water Cherenkov (HAWC) Gamma-ray Observatory in the high mountains of Mexico was completed in March of 2015 and is now giving us a new view of the TeV sky. HAWC is 15 times more sensitive than the previous generation of wide-field EAS gamma-ray instruments and is able to detect the Crab nebula at 5σ with each daily transit. Unlike Imaging Atmospheric Cherenkov Telescopes...
Mr
Xavier Rodrigues
(DESY)
27/08/2018, 17:20
The origin of the astrophysical neutrinos detected by IceCube, whose energies extend up to a few PeV, is still unknown.
In this work we investigate blazars (a class of relativistic jets from the core of active galaxies) as sources of the diffuse astrophysical neutrino flux.
For a blazar of a given luminosity, we calculate the emitted neutrino spectrum using a recently developed numeric...
Dr
Tomohisa Kawashima
(National Astronomical Observatory of Japan)
27/08/2018, 17:25
Ultra-luminous X-ray sources (ULXs) are extragalactic, off-nucleus, point-like X-ray sources with enormous luminosity $> 10^{39} ~[{\rm erg}~{\rm s}^{-1}]$, which exceeds the Eddington limit for stellar-mass black holes. Because of such a large luminosity, ULXs are expected to be powered by the super-Eddington accretion onto neutron stars or stellar-mass black holes, or sub-Eddington accretion...
Dr
Kimberly Boddy
(Johns Hopkins University)
27/08/2018, 17:30
There is a substantial effort in the physics community to search for dark matter interactions with the Standard Model of particle physics. Collisions between dark matter particles and baryons exchange heat and momentum in the early Universe, enabling a search for dark matter interactions using cosmological observations in a parameter space that is highly complementary to that of direct...
Mr
Michael Kreter
(University of Wuerzburg)
27/08/2018, 17:35
We have previously argued that the probability for the detection of individual neutrinos from individual blazars is expected to scale with the long-term fluence rather than short flares of high gamma-ray flux. Recently, the extremely high energy (EHE) muon neutrino event IceCube-170922A was found to coincide with increased gamma-ray emission from the blazar TXS 0506+056. We use short- and...
Dr
Fabian Schussler
(CEA-Saclay)
27/08/2018, 17:35
Fabian Schüssler for the CTA consortium
The Cherenkov Telescope Array (CTA) is the next generation high-energy gamma-ray observatory using the Imaging Air Cherenkov Telescope (IACT) technique. It will improve the sensitivity level of current instruments by an order of magnitude, provide energy coverage for photons from 20 GeV to at least 300 TeV to reach to high redshifts and extreme...
Mr
Shotaro Yamasaki
(University of Tokyo)
27/08/2018, 17:45
Most fast radio bursts (FRB) do not show evidence of repetition, and such non-repeating
FRBs may be produced at the time of a merger of binary neutron stars (BNS), provided
that the BNS merger rate is close to the high end of the currently possible range. However,
the merger environment is polluted by dynamical ejecta, which may prohibit the
radio signal from propagating.We examine this by...
Christoph Raab
(Université Libre de Bruxelles)
27/08/2018, 17:50
Blazars are active galactic nuclei which have their relativistic particle jet pointing towards Earth and have been observed to emit gamma rays to very high energies. They are also candidates for the yet-unknown accelerators of ultra-high-energy cosmic rays. In such a scenario, their gamma-ray emission might be associated with neutrinos produced by hadronic interactions in the jet. Correlating...
Dr
Kumiko Kotera
(Institut d'Astrophysique de Paris)
28/08/2018, 09:30
The violent Universe still defies us, as the sources of ultra-high-energy cosmic rays remain unknown. Yet we have drastically increased the amount of information at very high energies in the last 5 years, with combined observations of cosmic rays, gamma rays, neutrinos, and gravitational waves. We will identify in this talk the multi-messenger data that can be relevant to solve this...
Prof.
Tony Bell
(University of Oxford)
28/08/2018, 10:00
We discuss the possibility that ultra-high energy cosmic rays (UHECR) may be accelerated by shocks in the lobes of radio galaxies. Acceleration at the termination shocks of jets is problematic because relativistic shocks are poor accelerators to high energy. We show that non-relativistic shocks with suitable Hillas parameters occur in plasma streams flowing out of the jet termination regions...
Mr
Julien Wulf
(University of Zurich)
28/08/2018, 14:00
Observations at cosmological and astronomical scales indicate that the majority of matter in our Universe is in the form of non-relativistic and long-lived dark matter. Its observed relic abundance is consistent with the existence of a neutral, massive particle with little or no self-interaction. A dark matter candidate favoured by extensions of the Standard Model is a Weakly Interacting...
Prof.
Sherry Suyu
(Max Planck Institute for Astrophysics / Technische Universität München)
28/08/2018, 14:00
Strong gravitational lenses with measured time delays between the multiple images can be used to determine the Hubble constant that sets the expansion rate of the Universe. Measuring the Hubble constant is crucial for inferring properties of dark energy, spatial curvature of the Universe and neutrino physics. I will describe techniques for measuring the Hubble constant from lensing with a...
Prof.
Martin Erdmann
(RWTH Aachen University)
28/08/2018, 14:00
The Pierre Auger Observatory in Argentina is the world's largest observatory for measuring ultra-high energy cosmic rays with an observation area of 3000 km2. The atomic nuclei arriving from outer space reach the highest energies observed in nature. Clues to their origin come from studying the distribution of their arrival directions. We discuss an anisotropy observed at more than the 5 sigma...
Hendrik Hildebrandt
(Universität Bonn)
28/08/2018, 14:15
Gravitational lensing represents a unique tool to study the dark
Universe. Small distortions in the images of galaxies caused by the
gravitational lensing effect of the matter distribution in the Universe
can be detected over the whole sky. Measuring these coherent distortions
makes dark matter structures "visible", allows us to study their growth
over cosmic time, and yields cosmological...
Dr
Dmitri Ivanov
(University of Utah)
28/08/2018, 14:15
Telescope Array (TA) is a cosmic ray detector in the Northern hemisphere that measures cosmic rays of energies from 1 PeV to 100 EeV and higher. TA is a hybrid detector that consists of a ground array of scintillation counters, covering 700 km$^2$ on the ground, and overlooked by the three fluorescence detector stations. Sensitivity of TA has been extended by the TA low energy extension...
Sebastian Baum
(OKC & Stockholm University)
28/08/2018, 14:20
Recently, the DAMA/LIBRA collaboration released updated results from their search for the annual modulation signal from Dark Matter scattering in the detector. Besides approximately doubling the exposure of the DAMA/LIBRA data set, the updated photomultiplier tubes of the experiment allow to lower the recoil energy threshold to 1 keV electron equivalent from the previous threshold of 2 keV...
Dr
Ng Kenny Chun Yu
(Weizmann Institute of Science)
28/08/2018, 14:20
I will discuss recent results on gamma-ray observations of the Sun with Fermi, which revealed many interesting and surprising features. These gamma rays are expected to be produced by hadronic interactions between cosmic rays and the solar atmosphere. The high flux of gamma rays observed from the Sun requires a large boost of gamma-ray production by some mechanism, which is likely related to...
Ms
Anastasia Sokolenko
(University of Oslo)
28/08/2018, 14:30
In this talk, we discuss the relation between the strength of the self-interaction of dark matter (SIDM) particles and the predicted properties of the inner density distributions of dark matter (DM) halos. We present the results of N-body simulations for 28 halos performed for the same initial conditions for cold DM and for SIDM with different cross-sections.
We provide a simple...
Prof.
Sergey Troitsky
(INR, Moscow)
28/08/2018, 14:30
Telescope Array observes ultra-high-energy cosmic rays in the Northern hemisphere for 10 years, and the statistics starts to allow for studies of the cosmic-ray flux not only averaged over the field of view, but direction-dependent. I review recent Telescope Array results and future plans related to anisotropy of arrival directions and direction-dependent studies of the energy spectrum and...
Eva Leser
(Universität Potsdam/ DESY, D-15738 Zeuthen, Germany)
28/08/2018, 14:35
Eta Car is a colliding-wind binary composed of a massive luminous blue variable (~100 solar masses) and a companion star of O or B-type (~ 30 solar masses). Its orbit is very eccentric and has a period of 2023 days. Although the binary has a rich observational history in, e.g. the optical regime, strong experimental evidence for gamma-ray emission from the system has built up only recently. It...
Paolo Gorla
(Laboratori Nazionali del Gran Sasso - INFN)
28/08/2018, 14:40
The CRESST-III (Cryogenic Rare Event Search with Superconducting Thermometers) experiment, located in the Gran Sasso underground laboratory (LNGS, Italy), aims at the direct detection of dark matter (DM) particles.
Scintillating CaWO$_4$ crystals operated as cryogenic detectors at mK temperatures are used as target material for elastic DM-nucleus scattering. The simultaneous measurement of...
Dr
Andrey Saveliev
(Immanuel Kant Baltic Federal University)
28/08/2018, 14:45
Primordial Magnetic Fields (PMFs), being present before the epoch of cosmic recombination, induce small-scale baryonic density fluctuations. These inhomogeneities lead to an inhomogeneous recombination process which alters the peaks and heights of the large-scale anisotropies of the Cosmic Microwave Background (CMB) radiation. Utilizing numerical compressible MHD calculations based on kinetic...
Dr
Matthias Plum
(Marquette University)
28/08/2018, 14:45
IceTop is the surface component of the IceCube Observatory at the South pole and consists of ice-cherenkov detector stations at the top of IceCube's strings.
The air shower data are analyzed to study the cosmic ray spectrum and composition in the energy range from PeV to EeV.
The shower size $S_{125}$ from IceTop alone can be used as a proxy for estimating the primary energy, and unfolded...
Mr
Matteo Balbo
(ISDC, Univeristé de Genève)
28/08/2018, 14:50
The $\eta$ Carinae binary system hosts one of the most massive stars and has the highest known mass-loss rate. This dense wind encounters the much faster wind expelled by the stellar companion, dissipating mechanical energy in the shock. In these regions, particles are accelerated to very-high-energies via diffusive shock acceleration and subsequently cooled via inverse-Compton and photo-pion...
Prof.
Daniele Martello
(INFN Lecce)
28/08/2018, 15:00
The Pierre Auger Observatory with its exposure provides us with a large set of excellent data. The analysis of these data has led to major breakthroughs in the last decade, but a coherent interpretation has not yet been achieved. New questions have emerged, including that of the composition of cosmic rays in the energy region of the flux suppression, which is of key importance for making...
Nassim Bozorgnia
(Durham University)
28/08/2018, 15:00
A precise knowledge of the local dark matter velocity distribution and its uncertainties is necessary for the correct interpretation of dark matter direct detection data. High resolution hydrodynamical simulations of galaxy formation provide important information on the properties of the dark matter halo, and find that baryons generally make the local dark matter velocity distribution of Milky...
Dr
Klaus Reitberger
(Zentrum für Astronomie,Universität Heidelberg AND Institut für Astro- und Teilchenphysik, Universität Innsbruck)
28/08/2018, 15:05
In the light of new data regarding the high-energy $\gamma$-ray emission of suspected massive star colliding-wind binary systems, magneto-hydrodynamic simulations can now be refined and adapted in order to provide explanation of past and prediction of future emission characteristics of these sources.
We use three-dimensional magneto-hydrodynamic modeling to investigate the structure and...
Dr
Toshihiro Fujii
(Institute for Cosmic Ray Research, University of Tokyo)
28/08/2018, 15:15
The origin and nature of ultrahigh-energy cosmic rays (UHECRs) are one of the most intriguing mysteries in Astroparticle Physics. The two giant observatories, Telescope Array Experiment and Pierre Auger Observatory, are steadily observing UHECRs in both hemispheres. We highlight their latest results and address the requirements for a next-generation observatory.
The Fluorescence detector...
Prof.
Jochen Schieck
(HEPHY OeAW)
28/08/2018, 15:15
The sub-GeV mass region of the dark matter is foreseeably to be explored intensively in the next generation of direct detection experiments. Essig and others [1] recently discussed the feasibility of detecting the dark-matter electron recoil using low-noise semiconductor detectors as the active target. With a readout noise level below one electron RMS, the sensitivity allows us to test several...
Prof.
Urjit Yajnik
(IIT Bombay)
28/08/2018, 15:15
Exclusion of several classes of models due to LHC and astroparticle data has revived interest in grand unification. Typical unified theories predict topological defects. We study a particular SUSY SO(10) model which can produce transitory domain walls near grand unification scale, comparable to the scale of onset of low field inflation. While topologically not stable, the D-parity domain walls...
Mr
Chang Dong Rho
(University of Rochester)
28/08/2018, 15:20
Astrophysical sources of high-energy radiation such as AGN and microquasars produce relativistic jets. Particle acceleration in jets is theoretically well-motivated, but direct evidence of acceleration in jets has not been observed above a few TeV. Using 33 months of data from HAWC, we present evidence for the production of gamma rays >10 TeV in the jets of SS 433, one of the most powerful...
Martin Krauss
(Chalmers University of Technology)
28/08/2018, 15:30
The discovery of dark matter (DM) at XENONnT or LZ would place constraints on DM particle mass and coupling constants. It is interesting to ask when these constraints can be compatible with thermal production of DM. We address this question within the most general set of renormalizable models that preserve Lorentz and gauge symmetry, and that extend the standard model by one DM candidate of...
Prof.
Igor Yashin
(National Research Nuclear University MEPhI)
28/08/2018, 15:30
The new approach to investigations of inclined muon bundles, based on the local muon density spectra (LMDS) phenomenology allows to study primary cosmic rays in a wide energy interval from 10^15 up to 10^19 eV. The features of the proposed method for studying EAS are discussed. The transverse dimensions of EAS rapidly increase with increasing of the zenith angle and, hence, EAS in a wide...
Joshua Cardenzana
(Institut de Recherche en Astrophysique et Planétologie)
28/08/2018, 15:45
The upcoming Cherenkov Telescope Array (CTA) will provide a significant
improvement in both sensitivity and angular resolution compared to current
generation imaging atmospheric Cherenkov telescopes. A key science goal of
CTA is a survey of the entire Galactic plane. Outcomes of this survey include a
census of Galactic gamma-ray source populations (SNR, PWNe, binaries,...
Mr
said TALBAOUI
(Laboratory of Materials Physics)
28/08/2018, 15:45
S. TALBAOUI, H. GRIMECH, E. BAQLOUL, M.HABBAD
Laboratory of Materials Physics, Faculty of Sciences and Technologies, Sultan Moulay
Slimane University, Beni Mellal, Morocco
Abstract
One of the most important issues in astrophysics and cosmology is understanding the nature of dark matter. One...
Dr
Henrike Fleischhack Fleischhack
(Michigan Tech)
28/08/2018, 15:45
For the HAWC Collaboration.
Supernova Remnants (SNRs) have long been postulated to be the main sources of Galactic Cosmic Rays (CRs) up to the knee. However, while some SNRs have been shown to be CR accelerators, none of them have been confirmed to accelerate CRs beyond hundreds of TeV. The TeV gamma-ray emission from SNRs provides important information about the maximum energies to which...
Mr
Nathan Kelley-Hoskins
(DESY)
28/08/2018, 15:45
Revealing the nature of Dark Matter (DM) is a key objective of the current physical paradigm. Due to its predicted DM density at sub-pc distances, the Galactic Center should have a high number of DM interactions, making it a primary astrophysical source for DM studies. Various particle theories predict that DM annihilations over astrophysical scales can result in a gamma-ray flux. VERITAS is a...
Mr
Vikas Joshi
(Max-Planck-Institut für Kernphysik)
28/08/2018, 15:45
Traditionally for the extensive air shower arrays, the reconstruction of the gamma-ray induced air showers properties: such as core, energy and the depth of the shower maximum (X$_{max}$) is done by the model-dependent fit of the observed lateral amplitude distribution. This approach has certain disadvantages owing to the limitations of the fit models and procedures. To ameliorate this, we...
Mr
Andrea Turcati
(Technical University Munich)
28/08/2018, 15:45
Over the last few years the IceCube Neutrino Telescope has reported the first observations of an high-energy astrophysical neutrino flux. Recently, these observations have been strengthened by the publication of a sample of 82 high-energy starting events (HESE), and 36 high-energy muon neutrino tracks. Many different scenarios for the astrophysical origin of the IceCube neutrinos have been...
Mr
Joseph Lundeen
(Los Alamos National Laboratory)
28/08/2018, 15:45
The High Altitude Water Cherenkov Observatory (HAWC) is a very high energy (500 GeV to 100 TeV) gamma ray detector located in southern Mexico. HAWC has both a wide field of a view and near-continuous duty cycle, making it ideal for unbiased sky surveys. We use HAWC data to perform such a search for gamma ray signals from "dark dwarfs"; dark matter sub-halos with no optical counterpart. ...
Mr
Thomas Kintscher
(DESY)
28/08/2018, 15:45
The IceCube neutrino observatory is a 1 km³ detector deployed deep into the Antarctic ice sheet. While IceCube has recently discovered a diffuse astrophysical flux of high energy neutrinos, its source is yet to be identified.
With a field of view covering the whole sky and continuous data-taking, IceCube is capable of detecting transient sources when one or more high-energy neutrinos arrive,...
Jean-François Glicenstein
(IRFU, CEA-Saclay)
28/08/2018, 15:45
The use of gravitational time delays of macro-lenses to constrain the photon mass and the Lorentz Invariance Violation scale is investigated. The influence of photon masses on the measured time delays of macro-lenses is derived. The sensitivity of time delays to the photon mass is illustrated by a bound obtained from 3 AGN which have measurements in several passbands. The bound obtained is...
Dr
Nelson Videla
(Pontifical Catholic University of Valparaíso)
28/08/2018, 15:45
In multi-field reheating after modular $j$-inflation we investigate the conditions under which baryogenesis via non-thermal leptogenesis can be successfully realized. We introduce three heavy right-handed neutrinos to the non-supersymmetric standard model of particle physics, assuming hierarchical neutrino masses. Considering a typical mass for the first right-handed neutrino of the order of...
Dr
Bradley Kavanagh
(GRAPPA, University of Amsterdam)
28/08/2018, 15:45
The observation of gravitational waves from binary black hole mergers has renewed interest in the possibility of primordial black holes (PBHs) that are around 10 to 100 times more massive than the Sun. Such PBHs may form large numbers of binaries before matter-radiation equality and, if these binaries survive until today, they may contribute to the merger rate observable by LIGO and Virgo....
Mr
Joshua Foster
(University of Michigan)
28/08/2018, 15:45
Cosmological inflation generates primordial density perturbations which are scale-free on observable scales but that may be considerably larger on smaller scales. The boosted power spectrum at small scales leads to increased formation of dense, small-scale structure at early times, enhancing the present-day annihilation rate of annihilating dark matter. In this work, we show how to compute the...
Dr
Joshua Eby
(Weizmann Institute of Science)
28/08/2018, 15:45
Models of TeV-scale dark matter are severely constrained by increasingly precise direct detection experiments. One paradigm which can evade these bounds is Inelastic Dark Matter (iDM), where a nontrivial dark sector contains two particles with a small mass splitting $\delta$. A typical example is a supersymmetric model in which the two lightest Higgsinos have TeV-scale masses, and the heavier...
Mrs
Sabina Pürckhauer
(Max-Planck Institut für Kernphysik)
28/08/2018, 15:45
In this presentation, the performance of a template-based event reconstruction algorithm
will be shown for the first time for the Cherenkov Telescope Array (CTA), the next gen-
eration ground-based instrument for gamma-ray astronomy. In the Image Pixel-wise fit for
Atmospheric Cherenkov Telescopes (ImPACT) the charge measured in each camera pixel of
each telescope during an extended air...
Prof.
Diego Restrepo
(Professor)
28/08/2018, 15:45
We propose a simple theory for the idea that cosmological dark matter (DM) may be present today mainly in the form of stable neutral hadronic thermal relics. In our model neutrino masses arise radiatively from the exchange of colored DM constituents, giving a common origin for both dark matter and neutrino mass. The exact conservation of B−L symmetry ensures dark matter stability and the Dirac...
Ms
Niki Klop
(GRAPPA institute, University of Amsterdam)
28/08/2018, 15:45
The recent results of the EDGES collaboration indicate that during the era of reionization, the primordial gas was much colder than expected. The cooling of the gas could be explained by interactions between dark matter (DM) and particles in the primordial gas. Constraints from cosmology and particle experiments indicate that this DM should be light (~10-80 MeV), mili-charged, and only make up...
Mr
Andrii Petrashyk
(Columbia University)
28/08/2018, 15:45
The 9.7m Schwarzschild-Couder (SC) medium-sized telescope is a candidate for the Cherenkov Telescope Array (CTA). It exploits a novel aplanatic two-mirror optical design to provide a large field of view of 8 degrees and improved angular resolution across the whole field of view compared to single-mirror designs. In addition, the reduced plate scale of the camera allows the use of compact, high...
Dr
Ekrem Oguzhan Angüner
(CPPM)
28/08/2018, 15:45
One of the major scientific objectives of the future Cherenkov Telescope Array (CTA) Observatory is the search of PeVatrons. PeVatrons are the cosmic-ray factories able to accelerate nuclei at least up to Peta-electronvolt (1 PeV = 10$^{15}$ eV) energies. CTA will perform the first survey of the full Galactic plane at TeV energies and beyond with unprecedented sensitivity. The determination of...
Mr
Yoann GÉNOLINI
(Univ. of Brussels (ULB))
28/08/2018, 15:45
If DM interacts with nucleons and/or electrons it can be trapped by astrophysical objects such as the Sun or neutron stars. Elastic scattering of a DM particle with ordinary matter can in particular reduce the kinetic energy of the DM particle when it passes through these stars, such that its speed passes below the corresponding escape velocity. Once gravitationally trapped, DM undergoes...
Prof.
A. MURAT GULER
(Middle East Technical University)
28/08/2018, 15:45
A variety of experiments have been developed over the past decades, aiming at the detection of Weakly Interactive Massive Particles (WIMPs) via their scattering in an instrumented medium. The sensitivity of these experiments has improved with a tremendous speed, thanks to a constant development of detectors and analysis methods. Detectors capable of reconstructing the direction of...
Mr
Cédric Perennes
(LPNHE - Paris)
28/08/2018, 15:45
In the past 15 years, Cherenkov Telescopes have detected various minute-scale flares of AGNs in the energy range above 100 GeV. This important sample allows for measurements of corresponding light curves and energy spectra leading to a precise determination of possible photon energy dependent time delays.
Analyses were performed in order to study possible effects of these distant and...
Mr
Mirko Bunse
(TU Dortmund)
28/08/2018, 15:45
Obtaining the energy spectrum of an astrophysical source is crucial for our understanding of the source properties and the underlying physical principles, e.g. the acceleration of cosmic rays. In Imaging Air Cherenkov Astronomy and neutrino astronomy, however, the reconstruction of spectra is hindered by the fact, that the energy of the primary particle cannot be accessed experimentally, but...
Dr
Giorgio Galanti
(INAF, Osservatorio Astronomico di Brera)
28/08/2018, 15:45
Axion-like particles (ALPs) are very light, neutral, pseudo-scalar bosons
which are supposed to interact with two photons. They can give rise to
very interesting astrophysical effects taking place in the very-high
energy band and above (10 GeV – 1000 TeV) when an external magnetic field
is present. We analyze the propagation of the photon-ALP beam generated as
pure photons at the jet base...
Prof.
Don Ellison
(North Carolina State University)
28/08/2018, 15:45
First-order Fermi particle acceleration in supernova remnant (SNR) shocks is generally considered as the most likely production mechanism for the bulk of the cosmic rays (CRs), i.e., those with energies below the knee at $\sim 10^{15}$ eV. The SNR origin of higher energy CRs remains uncertain since the shock speeds of typical SNRs are too small to produce CRs above $\sim 10^{16}$ eV in the...
Antonia Hubbard
(Northwestern University)
28/08/2018, 15:45
The Micro-X High Resolution Microcalorimeter X-Ray Imaging Rocket is a sounding rocket mission that launched on July 22, 2018. This was the first successful operation of Transition Edge Sensors (TESs) and SQUID Time-Division Multiplexing in space. This milestone demonstrates the flight readiness of these technologies and establishes a new type of detector for X-ray astronomy. Micro-X is...
Ms
Armelle Jardin-Blicq
(Max Planck Instiute für Kernphysik)
28/08/2018, 15:45
The High Altitude Water Cherenkov (HAWC) γ-ray observatory is fully operational since march 2015 in central Mexico. It is a Water Cherenkov Detector (WCD) consisting of 300 tanks filled with purified water, each instrumented with 4 photomultiplier tubes. They record, via the cherenkov light produced in the water, the secondary particles from atmospheric air showers of energy ranging from 0.1...
Mr
Giacomo D'Amico
(University of Rome "La Sapienza")
28/08/2018, 15:45
I will present a flavor and energy inference analysis (Astroparticle Physics, Volume 101, 2018) for each high-energy neutrino event observed by the IceCube observatory during six years of data taking. For each event the main observables in the IceCube detector are the deposited energy and the event topology (showers or tracks) produced by the Cherenkov light by the transit through a medium of...
Dr
Henrike Fleischhack Fleischhack
(Michigan Tech)
28/08/2018, 15:45
On behalf of the SGSO Consortium.
The field of Very-High-Energy (VHE, E>100 GeV) gamma-ray astronomy is entering an era of precision measurements. Over the last decade, innovations in instrumentation have led to a drastically improved understanding of the most energetic objects in the Universe. New results by the High Altitude Water Cherenkov Observatory (HAWC) have shown the unique...
Prof.
Wlodek Bednarek
(University of Lodz)
28/08/2018, 15:45
Gamma-ray emitting FR I type radio galaxies are expected to be aligned at large angles to
the line of sight. We consider a scenario which naturally explains the energetic gamma-ray emission from radio galaxies. It is proposed that two emission regions are present in the jet at this same moment, the inner fast moving blob produces radiation strongly collimated along the jet axis and the...
Dr
Denis Bernard
(LLR, CNRS/IN2P3)
28/08/2018, 15:45
gamma-ray astronomy is polarization-blind as no significant
polarimetry of a cosmic source has been performed since the [OSO-8 measurement on the Crab nebula][1] in the X-ray band.
gamma-ray polarimetry would enable to [tag the curvature-synchrotron radiation transition in pulsars][2], to [decipher leptonic from hadronic
radiation models for blazars][3] .. and [much more][4].
We...
Dr
Mauricio Bustamante
(Niels Bohr Institute)
28/08/2018, 15:45
Progress in finding the origin of ultra-high-energy cosmic rays (UHECRs) will come from discovering the secondary UHE neutrinos produced in UHECR interactions. Yet, the flux of UHE neutrinos may lie beyond the reach of existing detectors and their possible upgrades. GRAND is a planned large-scale UHE observatory designed to discover UHE neutrinos even if their flux is low. It will do so by...
Ms
Ruiz-Velasco Edna
(Max-Planck-Institut für Kernphysik)
28/08/2018, 15:45
Fermi-LAT observations have proven that GeV gamma-ray emission is a relatively common feature for many gamma-ray bursts (GRBs). However, the relatively low effective area of space detectors implies low statistics for the highest energy photons which impedes detailed physical interpretation. The highest energy photon detected by LAT reached 95 GeV, a range which is well within reach for...
Jean-François Glicenstein
(IRFU, CEA-Saclay)
28/08/2018, 15:45
PKS 1830-211 is a known macrolensed AGN located at a redshift of z=2.5. Its high energy gamma ray emission has been detected with the Fermi-LAT instrument and evidence for lensing was obtained by several authors from its high energy data.?Aims. Observations of PKS 1830-211 were taken with the H.E.S.S. array of Imaging Atmospheric Cherenkov Telescopes in August 2014, following a flare alert by...
Dr
Michael Zacharias
(TPIV, Ruhr-Univseristät, Bochum, Germany)
28/08/2018, 15:45
The governing process behind the variability of blazars is still unknown. Hence, the collection of long-term data on individual sources is an important step in order to unlock this unknown. The flat spectrum radio quasar (FSRQ) PKS 1510-089 has been observed by H.E.S.S. at VHE gamma-rays (E>100GeV) since the discorvery in 2009. A much denser monitoring effort has been started in 2015 in order...
Dr
Fabian Schussler
(CEA-Saclay)
28/08/2018, 15:45
Fabian Schüssler on behalf of the H.E.S.S. Collaboration
The detection of an astrophysical flux of high-energy neutrinos by IceCube is a major step forward in the search for the origin of cosmic rays, as this emission is expected to originate in hadronic interactions taking place in or near cosmic-ray accelerators. No neutrino point sources, or significant correlation with known...
Mr
Dimitrios Kantzas
(UvA/API/GRAPPA)
28/08/2018, 15:45
Cygnus X-1 is the first Galactic source confirmed to host a black hole and has been observed since then across the whole electromagnetic spectrum. Recently, it was also detected in the 0.1-10 GeV band by Fermi/LAT and possibly detected at low significance by MAGIC during a flare. The source's non-thermal radiation is thought to originate from the relativistic jets launched by the black hole...
Prof.
Wlodek Bednarek
(The University of Lodz)
28/08/2018, 15:45
AR Scorpii, close binary system of a rotation powered white dwarf and a low mass M type companion star, shows non-thermal emission extending up to the X-ray energy range. We propose that relativistic electrons and hadrons can be accelerated in a strongly magnetised, turbulent region formed in collision of a rotating white dwarf magnetosphere and a dense atmosphere of the M dwarf star. The...
Mrs
Iryna Lypova
(DESY, Zeuthen)
28/08/2018, 15:45
The High Energy Stereoscopic System (H.E.S.S.) is an array of Cherenkov telescopes in Namibia and operates in the energy range from a few tens of GeV to more than 50 TeV. Most of the very-high-energy sources visible with H.E.S.S. emit gamma rays with energies up to tens of TeV. Nominal analysis methods, however, are optimised for the TeV energy range and achieve the best sensitivity at $\sim$1...
Mr
Christian Haack
(RWTH Aachen University)
28/08/2018, 15:45
Many neutrino interactions measured by the IceCube Neutrino Observatory produce only hadronic showers, which appear as almost point-like light emission due to the large detector spacing (~125m).
At PeV energies these showers often saturate the PMTs closest to the interaction vertex - thus the reconstruction has to rely on more diffused photons which requires precise understanding of
the...
Mr
Cédric Perennes
(LPNHE - Paris)
28/08/2018, 15:45
Studying the arrival times of γ-ray photons according to their energy puts constraints fundamental physics such as Lorentz Invariance Violation (LIV) signatures but can also provide specific information about the emitting sources themselves. Observing the time evolution of AGN spectra can significantly constrain *in situ* physical parameters and radiative processes at work.
A...
Dr
Nissim Fraija
(Astronomy Institute)
28/08/2018, 15:45
Very-high-energy (VHE) photon detections from Gamma-ray bursts (GRBs) can provide compelling evidences about the radiative processes, physical composition of the ejecta and acceleration processes. The synchrotron radiation can only explain photons with energies less than < 10 GeV. In the framework of GRB fireball, we present a theoretical model based on synchrotron self-Compton forward...
Mrs
Ludmilla Dirson
(Uni of Hamburg)
28/08/2018, 15:45
The Crab nebula provides exceptionally bright non-thermal emission across the entire wavelength range from radio to the most energetic photons. The spatial and spectral structure of the non-thermal synchrotron emission is known in exceptional detail. The inverse Compton emission of the nebula has just recently been spatially resolved.
In this work, we reexamine the inverse Compton...
Mr
Christopher Eckner
(University of Nova Gorica)
28/08/2018, 15:45
A new measurement of a spatially extended gamma-ray signal from the center of M31 recently reported that the emission broadly resembles the Galactic center excess (GCE) of the Milky Way (MW).
In this contribution, we discuss the possibilities that the signal originates from a population of millisecond pulsars (MSPs), or alternatively the annihilation/decay of dark matter (DM) particles. An...
Prof.
Omar Kurtanidze
(Abastumani Observatory)
28/08/2018, 15:45
About fifty (Mrk 421, Mrk 501, 1ES 1959+650 and others) northern TeV extragalactic sources have been discovered during last twenty five years. Most of them (2/3) we are monitoring in Abastumani Observatory during 20 years using 125-cm and dedicated 70-cm meniscus telescopes. All observations (over 3100 nights) have been conducted with Apogee Ap6E and SBIG ST-6 CCD cameras in BVRI bands. The...
Mr
Thomas Edwards
(Grappa, University of Amsterdam)
28/08/2018, 15:45
Direct detection experiments are one of a few primary avenues for the potential detection of particle Dark Matter (DM). We introduce general new statistical methods to systematically study the model-discrimination power of these (and many other) instruments. In a nutshell, our approach allows one to study all possible benchmark models at once making general conclusions possible. As an...
Prof.
Makoto Narita
(National Institute of Technology, Okinawa College)
28/08/2018, 15:45
We show a global existence theorem for Gowdy symmetric spacetimes
with a positive potential as a model for inflationary cosmology
from string/M-theory.
Also, asymptotic behaviour of the spacetimes is investigated.
Asymptotically velocity terms dominated solutions
near the initial singularity are constructed
and the future asymptotic behaviour of the spacetimes is analysed.
These...
Dr
Maria Victoria del Valle
(Potsdam University)
28/08/2018, 15:45
Since the detection of non-thermal radio emission from the bow shock of a massive runaway star simple models have predicted high-energy emission from these Galactic sources. In this work we develop a more sophisticated model for the non-thermal emission from massive run-away star bow shocks. The main goal is to establish whether these systems are efficient non-thermal emitters or they are not...
Dr
Maria Magdalena Gonzalez
(Instituto de Astronomía, UNAM), Dr
Nissim Fraija
(Instituto de Astronomia, UNAM)
28/08/2018, 15:45
The SED of high-peaked BL Lacs is generally understood as a composition of synchrotron radiation in X-rays and self-synchrotron emission peaking at energies higher than MeV originated in one emission zone. Although most of the observations are well described by this model, orphan flares, lack of correlation between X-rays and gamma-rays and a broader SED in the gamma ray regime challenge the...
Mr
Xavier Rodrigues
(DESY)
28/08/2018, 15:45
We investigate non-thermal electron and nuclei energy losses within the remnant of the binary neutron star merger GW170817.
We demonstrate that if the non-thermal emission originates from synchrotron radiation of a Fermi shock accelerated electron population, then the absence of a cooling break from radio to X-rays can be used to constrain the magnetic field in the remnant to the mG level....
Rafael Alves Batista
(University of São Paulo)
28/08/2018, 15:45
TeV gamma-ray emission has been detected from non-blazar low luminosity active galactic nuclei (LLAGN), establishing them as potential cosmic-ray accelerators as well as sources of PeV neutrino emission. However, current observations cannot determine whether the TeV gamma rays come from the jet or from the black hole (BH) core region. In this work we consider numerical general relativitic MHD...
Dr
Petr Satunin
(INR, Moscow)
28/08/2018, 15:45
We discuss the loop-level process of photon splitting to three photons in quantum electrodynamics (QED) with broken Lorentz invariance at high energies. Concetrating to the model of standard QED with additional positive quartic term in photon dispersion relation, we calculate the rate of the process of photon splitting below the threshold of three-level process of photon decay to...
Dr
Norita Kawanaka
(Kyoto University)
28/08/2018, 15:45
Recently AMS-02 has reported the energy spectra of secondary cosmic-rays Li, Be, B up to a few TeV, which seem to be hardened above ~200GV. We discuss the production, acceleration, and escape of secondary cosmic-ray nuclei that are produced via spallation of primary cosmic-ray nuclei, such as C, N, and O in a supernova remnant (SNR) shock. Taking into account the energy-dependent escape of...
Dr
Andrey Timokhin
(NASA/GSFC)
28/08/2018, 15:45
Pulsars are among the most prominent gamma-ray sources observed by
Fermi. Despite the wealth of observational information and considerable efforts
of theorists we still do not know their exact emission mechanism(s). However, it
is widely agreed upon than pulsar activity is intimately connected to the
copious generation of electron-positron pairs in pulsar magnetosphere; a rapidly
rotating...
Mr
Dylan van Arneman
(University of Amsterdam), Mr
Marnix Reemst
(University of Amsterdam)
28/08/2018, 15:45
We investigate the radiative decay of the cosmic neutrino background,
and its impact on the spectrum of the cosmic microwave background (CMB) that is
known to be a nearly perfect black body.
We derive {\it exact} formulae for the decay of a heavier neutrino into
a lighter neutrino and a photon, $\nu_j \to \nu_i + \gamma$, and of
absorption as its inverse, $\nu_i + \gamma \to \nu_j$,...
19.
Primordial Anisotropies in the Gravitational Wave Background from Cosmological Phase Transitions
Dr
Geller Michael
(University of Maryland)
28/08/2018, 15:45
Phase transitions in the early universe can readily create an observable stochastic gravitational wave background. We show that such a background necessarily contains anisotropies analogous to those of the cosmic microwave background (CMB) of photons, and that these too may be within reach of proposed gravitational wave detectors. Correlations within the gravitational wave anisotropies and...
Mr
Robert Stein
(DESY Zeuthen)
28/08/2018, 15:45
Since the detection of high-energy cosmic neutrinos at the IceCube Neutrino Observatory in 2013, there has been an on-going search to find suitable transient or variable source candidates. Previous analyses testing Supernovae, GRBs and time-integrated Blazar emission have lead to constraints disfavouring these sources as dominant contributors to the observed neutrino flux. However, Tidal...
Oleg Popov
(Seoul Netional University of Technology and Science)
28/08/2018, 15:45
We propose that the radiative generation of the neutrino mass can be achieved by incorporating the kinetic mixing of fermion fields which arises radiatively at 1 loop level. As a demonstrative example of the application of the mechanism, we will present the particular case of Standard Model extension by U(1)$_D$ symmetry. As a result, we show how neutrino masses can be generated via kinetic...
Prof.
Chian-Shu Chen
(Department of Physics, Tamkang University)
28/08/2018, 15:45
Compact stellar objects such as neutron stars (NS) are ideal places for capturing dark matter (DM) particles. We study the effect of self-interacting DM (SIDM) captured by the nearby NS that can reheat NS to an appreciated surface temperature. Recently, DM self-interaction was considered as an negligible effect due to its small geometric cross section in NS. However, we will demonstrate when...
Dr
Ranjan Laha
(Johannes Gutenberg University Mainz)
28/08/2018, 15:45
Measuring precise all-flavor neutrino information from a supernova is crucial for understanding the core-collapse process as well as neutrino properties. We apply a chi-squared analysis for different detector setups to explore determination of νe spectral parameters. Using a long-term two-dimensional core-collapse simulation with three time varying spectral parameters, we generate mock data to...
Dr
Fabian Schussler
(CEA-Saclay)
28/08/2018, 15:45
Fabian Schüssler on behalf of the SGSO Alliance
The Southern Gamma-ray Survey Observatory (SGSO) is a proposed next-generation extensive air shower detector located at a high-altitude site in the mountains of South America. SGSO will be sensitive to astrophysical gamma rays and cosmic rays in the energy range between 100 GeV and 100 TeV. Its science case is build on three main pillars: SGSO...
Prof.
Sergey Troitsky
(INR, Moscow)
28/08/2018, 15:45
Carpet is an air-shower array at Baksan, Russia, equipped with a large-area muon detector, which makes it possible to separate primary photons from hadrons. We report first results of the search for primary photons with energies E>1 PeV, associated with IceCube neutrino flux, in the data obtained with Carpet-2 (175 square-meter muon detector). The installation was upgraded to Carpet-3 (410...
Mr
Kevin Almeida Cheminant
(Institute of Nuclear Physics Polish Academy of Science)
28/08/2018, 15:45
As gamma rays propagate from their sources of production to Earth, radiation-matter interactions can occur, leading to an effective screening of the incident flux. In the PeV-EeV range, the dominant energy loss mechanism for photons is the production of electron-positron pairs. These pairs can emit bremsstrahlung photons as they interact with local electromagnetic fields. These photons can...
Dr
Maria Magdalena González Sánchez
(Universidad Nacional Autónoma de México - Instituto de Astronomía), Dr
Nissim Illich Fraija Cabrera
(Universidad Nacional Autónoma de México - Instituto de Astronomía), Dr
Simone Dichiara
(Universidad Nacional Autónoma de México)
28/08/2018, 15:45
Gamma-ray bursts (GRBs) are one of the most captivating extragalactic astrophysical phenomena. These transient events have been widely proposed as bright sources of the most energetic cosmic rays and gravitational waves. With its wide field of view (~2 str) and >95% duty cycle, the High Altitude Water Cherenkov (HAWC) Observatory, installed at 4100 m a.s.l. in the state of Puebla (Mexico), is...
Mr
Chad Brisbois
(Michigan Technological University)
28/08/2018, 15:45
Recent work has suggested that spatially extended TeV emission from pulsars (TeV Halos), such as that seen corresponding to Geminga, Monogem, and HAWC J0543+233 is distinct from Pulsar Wind Nebulae seen in X-ray energies. The primary difference between the two is one of particle transport; for a PWN leptons are confined near the pulsar due to interactions between the pulsar wind and the...
Mr
Martin Vollmann
(Technical University of Munich)
28/08/2018, 15:45
In some models for WIMP dark matter, radiative corrections dominate over the LO contributions in the computation of annihilation cross sections relevant for indirect detection. These corrections need to be resummed to all orders in perturbation theory for theoretical predictions to be sensible.
In this talk I will employ -and briefly review- resummation methods that are traditionally used...
Dr
Daniele Fargion
(Physics Depart., ROME UNIVERSITY 1 and INFN)
28/08/2018, 15:45
The Uhecr anisotropy at tens EeV and at 60 EeV found by Auger maps overlap partially with the observed TeV anisotropy found by Argo and Hawc array detectors lastt decade.
We had proposed it since many years.
These combined signals offer a reading key to identify the Uhecr source names, their address and their secondary fragment tails.
Dr
Anabella Araudo
(Astronomical Institute of the Czech Academy of Sciences)
28/08/2018, 15:45
Supersonic and collimated bipolar jets are launched from the inner
regions of accretion discs in forming stars. Jets from young stellar objects
are well known thermal emitters.
However, non-thermal radio emission from a handful of protostellar jets
has been reported in the last years. The detection of
synchrotron radiation indicates the presence of relativistic electrons and
magnetic...
Dr
Luca Foffano
(University of Padova)
28/08/2018, 15:45
Blazars spectral energy distributions are dominated by non-thermal emission from the jet, consisting of two main bumps. For the so-called extreme blazars, these components each peak in the X-ray and GeV-TeV bands.
Recent TeV observations have revealed a few of these objects whose second peak exceeds several TeV (e.g. 1ES 0229+200). Such intriguing sources have been objects of different...
Sarah Mancina
(University of Wisconsin - Madison)
28/08/2018, 15:45
IceCube analyses which look for an astrophysical neutrino signal in the southern sky face a large background of atmospheric muons and neutrinos created in cosmic ray air showers. Selecting for events which start inside the detector suppresses not only the downgoing muon background, but also the southern sky atmospheric neutrino background by the energy- and declination-dependent atmospheric...
Dr
Michael Gustafsson
(Göttingen University)
28/08/2018, 15:45
The standard way to calculate the thermal relic abundance of dark matter relies on the assumption that the dark matter particles remain in kinetic equilibrium throughout the chemical freeze-out process. However, this assumption is not always justified. This talk aims to address how to handle such situations, i.e. when an early kinetic decoupling happens, and discuss the phenomenological...
Dr
Anabella Araudo
(Astronomical Institute of the Czech Academy of Sciences)
28/08/2018, 15:45
We study the effects of interaction of jets in
Active Galactic Nuclei when they encounter stellar
clusters passing across the inner jet. The interaction provides a scenario to address
non–thermal processes. In jet–star interactions a double bow–shock
structure is formed where particles get accelerated via diffusive
mechanism. Individual encounters have a limited effect, however,...
Mr
Chao Zhang
(IEXP/Univ.Hamburg)
28/08/2018, 15:45
The supersymmetric WIMP hypothesis is currently under scrutiny as there
is no experimental result supporting the existence a lightest
supersymmetric particle. The recent non-detection in large scale direct
detection experiments has demonstrated that a broader approach towards
dark matter particles is indicated. In this work, we show a simple
approach to convert constraints/sensitivities...
Dr
Jose Andres Garcia-Gonzalez
(IF-UNAM)
28/08/2018, 15:45
The HAWC gamma ray observatory is located at the Sierra Negra Volcano in Puebla, Mexico, at an altitude of 4,100 meters. HAWC is a wide field of view array of 300 water Cherenkov detectors that are continuously surveying ~ 2sr of the sky, operating since March 2015. The large collected data sample allows HAWC to perform an unbiased monitoring of blazars. One of the closest and brightest...
Dr
Hans Dembinski
(MPIK Heidelberg)
28/08/2018, 16:45
We present a new parametrisation of the cosmic-ray flux and its mass composition over an energy range from 1 GeV to 10^11 GeV. We combine measurements of the flux of individual elements from high-precision satellites and balloon experiments with indirect measurements of mass groups from the leading air shower experiments. We provide the first fit of this kind that consistently takes both...
Dr
Ruizhi Yang
(Max-Planck-Institut für Kernphysik)
28/08/2018, 16:45
We report the detection of diffuse gamma-ray emissions towards several massive star clusters in our Galaxy. The detailed spectral and spatial analysis reveal a remarkable constancy of the energy and radial distribution of the cosmic ray density,
w(E; r) ~ E^2.3 r^{-1} around these massive star clusters. The 1/r decrement of the CR density with the distance from the star cluster is a...
Dr
Simone Biagi
(INFN - Laboratori Nazionali del Sud)
28/08/2018, 16:45
The discovery of a cosmic neutrinos diffuse flux by IceCube together with the recent observation of gravitational waves have widened our spectrum of probes needed for multi-messenger astronomy. However, the origin of the faint flux of high-energy astrophysical neutrinos is still unknown. The ANTARES neutrino telescope is currently the detector with the largest sensitivity located in the...
Dr
Armando di Matteo
(ULB)
28/08/2018, 17:02
Charged particles of extraterrestial origin with energies in excess of 1018 eV (known as ultra-high-energy cosmic rays, UHECR) were first observed in the 1960s, and current-generation UHECR detectors have collected over 105 such events. Nevertheless, the interpretation of these data is not straightforward, and the sources of such particles are still unknown (but...
Mr
Chad Brisbois
(Michigan Technological University)
28/08/2018, 17:05
Since Galactic cosmic rays are observed in the PeV range, at least a few sources that accelerate particles to this energy (“PeVatrons”) should exist. A PeVatron is expected to have a hard, hadronic gamma-ray spectrum that extends to at least tens of TeV without any apparent spectral break or cutoff. High energy (> 100 TeV) gamma ray observations are therefore essential to the study of these...
Mr
Ore Gottlieb
(Tel Aviv Univesity)
28/08/2018, 17:05
Following a Neutron star merger a jet propagates and interacts with the out
owing
ejecta that surrounds the merger. As a result matter is pushed around the jet to form a hot cocoon which applies pressure on the jet and potentially collimates it. The cocoon envelops the jet as long as the jet propagates within the dense ejecta. After the jet breaks out, the cocoon expands and emits radiation...
Mr
Bing Theodore Zhang
(Peking University)
28/08/2018, 17:19
Recent results from the Pierre Auger Collaboration have shown that the composition of ultrahigh- energy cosmic rays (UHECRs) becomes gradually heavier with increasing energy. Although gamma- ray bursts (GRBs) have been promising sources of UHECRs, it is still unclear whether they can account for the Auger results because of their unknown nuclear composition of ejected UHECRs. In this work, we...
Mauricio Bustamante
(Niels Bohr Institute)
28/08/2018, 17:20
Progress in finding the origin of ultra-high-energy cosmic rays (UHECRs) will come from discovering the secondary UHE neutrinos produced in UHECR interactions. Yet, the flux of UHE neutrinos may lie beyond the reach of existing detectors and their possible upgrades. GRAND is a planned large-scale UHE observatory designed to discover UHE neutrinos even if their flux is low. It will do so by...
Dr
Troy Porter
(Stanford University)
28/08/2018, 17:20
High-energy gamma rays of interstellar origin are produced by the interaction of cosmic-ray (CR) particles with the diffuse gas and radiation fields in the Galaxy. The main features of this emission are well-understood and are reproduced by existing CR propagation models employing 2D Galactocentric cylindrically symmetrical geometry. However, the high-quality data from instruments like the...
Dr
Maria Victoria del Valle
(Potsdam University)
28/08/2018, 17:35
Since the detection of non-thermal radio emission from the bow shock of a massive runaway star simple models have predicted high-energy emission from these Galactic sources. In this work we develop a more sophisticated model for the non-thermal emission from massive run-away star bow shocks. The main goal is to establish whether these systems are efficient non-thermal emitters or they are not...
Dr
Krijn de Vries
(VUB/IIHE)
28/08/2018, 17:35
At the highest energies the cosmic neutrino flux drops rapidly and an even larger detection volume than the cubic kilometer of ice currently probed by the IceCube experiment is needed. Due to its long attenuation length, the radio signal provides the ideal means to cover such large volumes. Nevertheless, the direct radio emission from a neutrino induced particle cascade becomes detectable...
Ms
Claire Guépin
(Institut d'Astrophysique de Paris)
28/08/2018, 17:36
In addition to the emergence of time domain astronomy, the advent of multi-messenger astronomy opens up a new window on transient high-energy sources. Through the multi-messenger study of the most energetic objects in our universe, two fundamental questions can be addressed: what are the sources of ultra-high energy cosmic rays (UHECRs) and the sources of very-high energy neutrinos?
Jetted...
Dr
Tim Dietrich
(Nikhef (Dutch National Institute for Subatomic Physics))
28/08/2018, 17:45
With the detection of the binary neutron star merger GW170817 a new era
of multi-messenger astronomy started. GW170817 proved that neutron
star mergers are ideal laboratories to constrain the equation of state of
cold supranuclear matter, to study the central engines of short GRBs,
and to understand the origin and production of heavy elements.
In this talk, we discuss how the last...
Prof.
Wlodek Bednarek
(University of Lodz)
28/08/2018, 17:50
Massive stars with strong stellar winds are expected to be progenitors of the long gamma-ray
burtsts (GRBs). The winds of these stars are expected to form a wind cavities within the dense clusters. We consider a scenario in which protons, accelerated within the jet of GRB, escape from the GRB jet to the wind cavity. They are transported with the massive star wind to the dense open cluster...
Daniel Biehl
(DESY Zeuthen)
28/08/2018, 17:53
The origin of ultra-high energy cosmic rays (UHECRs) is still one of the biggest unsolved questions in astrophysics. We present a novel approach combining the knowledge about neutrinos and cosmic rays at the highest energies to give an alternative, joint solution to this question with Tidal Disruption Events (TDEs). TDEs are processes where stars are torn apart by the strong gravitational...
Dr
Tanja Hinderer
(Radboud University Nijmegen)
28/08/2018, 18:05
The gravitational waves from a neutron star binary inspiral carry unique information about fundamental physics in extreme conditions. I will discuss the imprints of the properties of neutron star matter on the gravitational waves, what we have learned from the neutron star binary inspiral event GW170817, and outline future prospects and challenges.
Matthias Huber
(TU Munich)
28/08/2018, 18:05
Located at the South Pole, the IceCube Neutrino Observatory is the world largest neutrino
telescope, instrumenting one cubic kilometre of Antarctic ice at a depth between 1450m
to 2450m. In 2013 IceCube reported the first observations of a diffuse astrophysical high-energy neutrino flux.
Although the IceCube Collaboration has identified more than 100 high energy neutrino events, the origin...
Tova Yoast-Hull
(Canadian Institute for Theoretical Astrophysics)
28/08/2018, 18:05
Recent analyses of the gamma-ray flux from Arp 220 have shown that the observed gamma-ray flux is larger than can be accounted for by the measured star formation rate. In contrast, the radio spectra observed for the galaxy's two nuclei are consisted with the observed rate. This indicates an excess of cosmic rays or additional cosmic ray population which produces more gamma-ray emission but...
Dr
Björn Eichmann
(Ruhr-Universität Bochum, Theoretische Physik IV)
28/08/2018, 18:10
Radio galaxies are intensively discussed as the sources of cosmic rays observed above about 3 EeV, called ultra-high energy cosmic rays (UHECRs).
The talk presents a first, systematic study that takes the individual characteristics of these sources into account, as well as the impact of the galactic magnetic field, as well as the extragalactic magnetic-field structures up to a distance of 120...
Dr
Alberto Sesana
(University of Birmingham)
28/08/2018, 18:25
Recent gravitational wave (GW) detections with LIGO/Virgo opened a new window on the Universe, unveiling the most violent catastrophic events in the cosmos. GW astronomy is just in its infancy, the Laser Interferometer Space Antenna (LISA) and Pulsar Timing Arrays (PTAs) will offer a complementary view of the GW universe in a much more extended range of frequencies, from mHz down to nHz. I...
Dr
David Sanchez
(CNRS/LAPP)
29/08/2018, 09:30
The current generation of Imaging Atmospheric Cherenkov Telescopes has its resolution power limited to few arcminute scale.
Recently, new simulations and analysis techniques, applied to H.E.S.S. observations, made possible the measure of the extension
of very high energy (VHE; E > 100 GeV) gamma-ray sources below one arcminute. The improved understanding of the point spread function...
Dr
Hao Zhou
(Los Alamos National Laboratory)
29/08/2018, 09:45
Nearby electron and positron accelerators, especially Pulsar Wind Nebulae, have been proposed as potential origins of the local multi-GeV positron excess. The HAWC Gamma-Ray Observatory has reported very extended TeV gamma-ray emission around two nearby middle-aged pulsars Geminga and B0656+14, suggesting ultra-relativistic electrons and positrons accelerated in our backyard. The gamma-ray...
Dr
Fabio Iocco
(ICTP-SAIFR), Dr
Fabio Iocco
(ICTP-SAIFR)
29/08/2018, 12:00
The distribution of Dark Matter in galaxies is one remarkable output of structure formation in a cosmological context, and an important input for the searches of the nature of Dark Matter. In this talk I will present the results of recent, fully data-driven analysis of the determination of the Dark Matter content in the Milky Way. I will also show how the uncertainties obtained with this...
Mr
Mathieu Boudaud
(LPTHE, Paris, France)
29/08/2018, 12:15
We take advantage of spacecraft Voyager 1's capacity for detecting interstellar CRs since it crossed the heliopause in 2012. This opens up a new avenue to probe DM through CR electrons and positrons in the sub-GeV energy range. From a complete description of the transport of electrons and positrons at low energy, we derive predictions for both the secondary astrophysical background and the...
Pasquale Migliozzi
(INFN Napoli)
29/08/2018, 14:00
Recently it has been reported by the IceCube detector, which is installed under the thick Antarctic ice, evidence of the existence of a high-energy flow of cosmic neutrinos.
Today, the scientific community requires that a neutrinos telescope located in the northern hemisphere verify and complete the results of IceCube, so as to allow observation of high-energy neutrinos across the sky. The...
Dr
Maria Vittoria Garzelli
(University of Delaware)
29/08/2018, 14:00
I will discuss the production of charm due to CR interactions in the atmosphere and the implications for astrophysical experiments. I will review both recent theoretical progress in QCD computations of prompt neutrino fluxes and recent developments and attempts of incorporating charm in hadronic interaction models traditionally used for studies of extended air showers.
Mr
Giacomo Principe
(ECAP - Erlangen Nurenberg University)
29/08/2018, 14:00
Previous analyses of point sources in the gamma-ray range were done only below 30 MeV (COMPTEL) or above 100 MeV (Fermi-Large Area Telescope). Below 30 MeV, the imaging Compton telescope (COMPTEL) detected 26 steady sources in the energy range from 0.75 to 30 MeV. At high energy, the LAT detects more than three thousand sources between 100 MeV and 300 GeV (3FGL). Since the Fermi-LAT detects...
Dieter Breitschwerdt
(Technische Universität Berlin)
29/08/2018, 14:00
During the last two decades due to the increase of computing power and software developments, such as adaptive mesh refinement, substantial progress has been made in numerical modeling of the interstellar medium (ISM). It has been found that the bulk of kinetic and thermal energy input stems from supernovae and to a lesser extent from stellar winds. Our group has shown that on mesoscales (1...
Dr
Sara Cutini
(INFN Perugia)
29/08/2018, 14:15
The gamma-ray emission in broad-line blazars is generally explained as inverse Compton (IC) radiation of relativistic electrons in the jet scattering optical-UV photons from the broad-line region (BLR), the so-called BLR external Compton (EC) scenario. We test this scenario on the Fermi gamma-ray spectra of 106 broad-line blazars detected with the highest significance or largest BLR, by...
Fabrizio Tavecchio
(Brera Observatory)
29/08/2018, 14:20
Despite intense inquiry, the sources at the origin of the high-energy neutrinos revealed
by IceCube are still unknown. The potential correlation of an IceCube event with a flaring
gamma-ray source has recently focused the attention on BL Lac objects, active galactic nuclei
with a relativistic jet pointing to the Earth. Since the nuclei of these sources lack bright
thermal components, it...
Prof.
Christoph Pfrommer
(AIP)
29/08/2018, 14:30
Star formation in galaxies appears to be self-regulated by energetic feedback processes. Among the most promising agents of feedback are cosmic rays (CRs), the relativistic ion population of interstellar and intergalactic plasmas. In these environments, energetic CRs are virtually collisionless and interact via collective phenomena mediated by kinetic-scale plasma waves and large-scale...
David Paneque
(Max Planck Institute for Physics)
29/08/2018, 14:30
Because of their brightness and proximity (z=0.03), Mrk421 and Mrk501 are among the very-high-energy gamma-ray objects that can be studied with the greatest level of detail. This makes them excellent astrophysical high-energy physics laboratories to study the nature of blazars. Since 2009, there has been an unprecedentedly long and dense monitoring of the radio to very-high-energy gamma-ray...
Dariusz Gora
(IFJ PAN, PL-31342 Krakow, Poland, DESY Germany)
29/08/2018, 14:40
A search for tau neutrino induced showers with the MAGIC telescopes is presented. The MAGIC telescopes located at an altitude of 2200 m a.s.l. in the Canary Island of La Palma, can point towards the horizon or a few degrees below, across an azimuthal range of about 80 degrees. This allows to search for a signature of particle showers induced by earth-skimming cosmic tau neutrinos in the PeV to...
Luca Foffano
(University of Padova, INFN)
29/08/2018, 14:45
On 22$^{\text{nd}}$ September 2017, a high energy neutrino was detected by the IceCube observatory in spatial coincidence with the blazar TXS 0506+056, which was observed to be flaring in the GeV band by the Fermi-LAT telescope. This coincidence triggered a series of multi-wavelength observations by several telescopes on ground and in space.
On 24$^{\text{th}}$ September 2017, the MAGIC...
Dr
Richard Tuffs
(Max-Planck-Institut fuer Kernphysik)
29/08/2018, 14:45
Using archival data from the Fermi Large Area Telescope in the 0.1 - 300$\,$GeV
photon energy range, we detect and characterise the gamma-ray emission
counterpart on parsec scales to the optically translucent, infrared-emitting
and dominantly neutral "Cirrus" clouds, which carry the bulk of gas mass in
the disk of the Milky Way at the solar circle. The detection is achieved using
a...
Binita Hona
(Michigan Technological University)
29/08/2018, 15:00
Massive Star clusters and Super bubbles in star forming regions (SFRs) have been postulated as possible sources of cosmic rays in our galaxy. At the interaction sites of stellar winds of O type stars, charged particles can be accelerated to TeV energies. One possible example of this is a Fermi-LAT cocoon, an extended region of gamma-ray emission detected by Fermi-LAT and attributed to a cocoon...
Dr
Alicja Wierzcholska
(Institute of Nuclear Physics PAS)
29/08/2018, 15:00
The catalogue of TeV gamma-ray emitting objects includes about 80 extragalactic sources, among which most are blazars.
Only a few of them belong to the class of radio galaxies or misaligned blazars.
The latter includes PKS 0625-354, an object that was detected in very high energy gamma rays within only 5.5 hours of H.E.S.S. observations.
Along with the H.E.S.S. observations, PKS 0625-354...
Dr
Michele Lucente
(CP3 - UCLouvain)
29/08/2018, 15:00
We provide the first systematic study of the low-scale leptogenesis scenario in the minimal Standard Model extended with 3 right-handed neutrinos having masses at the GeV scale.
We highlight and discuss the differences between the 2- and the 3-right-handed neutrino cases, the major qualitative distinction being the possibility, in the latter scenario, of probing part of the parameter space at...
Dr
Jean Alexandre
(King's College London)
29/08/2018, 15:10
Motivated by neutrino astronomy, we consider a plane wave of coupled and massive flavours, scattered
by a static black hole, and describe analytically and numerically the corresponding oscillation probability
in the surrounding space. Both the interpretation as particles travelling along geodesics and as scattered
waves are studied, and consistently show a non-trivial and potentially long...
Oleg Popov
(Seoul Netional University of Technology and Science)
29/08/2018, 15:15
The Standard Model of particle physics have been extremely successful so far, but there are still many unanswered questions like the origin of neutrino mass, nature of dark matter, the source of quark and lepton flavor mixing and their possible correlation, the theory of grand unification of all SM interactions. In this talk I will focus on some interesting models that attempt to answer these...
Naomi Tsuji
(Rikkyo University)
29/08/2018, 15:15
The shock waves at supernova remnants (SNRs) are the prominent acceleration sites of Galactic cosmic rays.
The diffusion of the accelerated particles around the SNR shock is assumed to be Bohm type, where the diffusion coefficient is proportional to the particle energy. The details, however, remain unrevealed.
There is a method to diagnose the diffusion coefficient from the cutoff shape of...
Dr
Jagdish Joshi
(University of Johannesburg)
29/08/2018, 15:15
The spectrum of UHECR signal events above 55 EeV from Centaurus A (Cen A) can provide a useful hint about the injected spectrum of cosmic ray nuclei. The injected spectrum connects UHECRs to the HESS detected GeV-TeV gamma rays. The 8 years of Fermi-LAT data from Cen A has significant hardening in the GeV energy. In an attempt to understand the origin of this hardening, we explore two emitting...
Dr
Mauricio Bustamante
(Niels Bohr Institute)
29/08/2018, 15:25
High-energy astrophysical neutrinos, with TeV--PeV energies, are acutely sensitive to the existence of potential new flavor-dependent interactions with the electrons around them. For the first time, we probe this possibility by looking for deviations in the flavor composition of the astrophysical neutrinos seen by IceCube. At these energies, the relative contribution of standard oscillations...
Valentina De Romeri
(IFIC (CSIC-Univ. Valencia))
29/08/2018, 15:30
Coherent neutrino-nucleus scattering can provide stringent constraints on generalised effective neutrino-quark interactions. While neutrino-quark non-standard interactions (NSI) represent a subset of these generalised interactions, in full generality they may include all possible four-fermion Lorentz structures.
Depending on their strength, these new interactions can sizably modify ...
Dr
Sergei Vafin
(Institute for Physics and Astronomy, University of Potsdam, D-14476 Potsdam, Germany)
29/08/2018, 15:30
Very high-energy gamma-rays from TeV blazars interact with the extragalactic background light producing pair beams. These pairs emit secondary photons in the GeV range by the inverse Compton scattering. However, the measured GeV signal is smaller compared to one predicted from the full electromagnetic cascade. From what follows that the pairs are affected by some other physical processes...
Dr
Daniel Castro
(Harvard-Smithsonian Center for Astrophysics)
29/08/2018, 15:30
Supernova remnant (SNR) N132D, located in the Large Magellanic Cloud, represents a unique opportunity for the study of gamma-ray emission from shock-accelerated cosmic rays (CRs) in another galaxy since it stands as the first and only extra-galactic SNR detected in gamma-rays. N132D is one of the brightest SNRs in the local Universe in the X-ray, infrared and radio bands, and it has also been...
Dr
Giovanni Morlino
(Gran Sasso Science Institute)
29/08/2018, 16:15
The Cosmic Ray (CR) physics has entered a new era driven by high precision measurements coming from direct detection (especially AMS-02 and PAMELA) as well as gamma-ray observations (Fermi-LAT) which requires the development of more refined models for the CR acceleration and propagation. In this talk I will present a model for the generation of the Galactic magnetic halo where Cosmic Rays...
Dr
Manuel Meyer
(Stanford University)
29/08/2018, 16:15
Almost 10 years of observations with the Fermi Large Area Telescope (LAT) have revealed extreme gamma-ray outbursts from flat spectrum radio quasars (FSRQs), temporarily making these objects the brightest gamma-ray emitters in sky. Yet, the location and mechanisms of the gamma-ray emission remain elusive. Here, we characterize the brightest flares of six FSRQs observed with the LAT. We find...
Dr
Klaus Eitel
(Karlsruhe Institute of Technology)
29/08/2018, 16:15
The EDELWEISS collaboration is performing a direct search for WIMP dark matter in the mass range from 1 to 20 GeV/c2 using cryogenic germanium detectors equipped with a full charge and thermal signal readout. We present the most recent results and the currently ongoing program to reduce the experimental thresholds in order to gain sensitivity for low mass WIMPs. This comprises utilizing the...
Dr
Christopher McCabe
(King's College London)
29/08/2018, 16:30
Direct detection experiments that utilise xenon have proven to be most sensitive for heavy (>5 GeV) dark matter particles. In this talk, I'll explore signals that allow xenon experiments to probe the dark matter - nucleon cross section for dark matter particles down to ~100 MeV. These signals arise from electron or photon emission from the xenon atom after a collision with a light dark matter...
Dr
Michael Zacharias
(TPIV, Ruhr-Univseristät, Bochum, Germany)
29/08/2018, 16:30
In late 2016 and early 2017, the flat spectrum radio quasar CTA 102 (z=1.032) experienced an extraordinary phase of its existence. Starting in October 2016, over the course of two months the gamma-ray flux rose by a factor 50 and decreased again for 2 months to pre-flare levels. This long-term trend has been superposed by short, bright flares, which made CTA 102 one of the brightest gamma-ray...
Ms
Claire Guépin
(Institut d'Astrophysique de Paris)
29/08/2018, 16:35
Diffuse TeV emission has been observed by H.E.S.S. in the Galactic Center region, in addition to the GeV gamma rays observed by Fermi. We propose that a population of unresolved millisecond pulsars located around the Galactic Center, suggested as possible candidates for the diffuse Galactic Center excess observed by Fermi, accelerate cosmic rays up to very high energies, and are thus also...
64.
Intranight variability of VHE gamma-ray emission during the outburst of PKS 1510-089 in May 2016
Dr
Julian Sitarek
(University of Lodz)
29/08/2018, 16:45
PKS 1510-089 is one of only a handful of flat spectrum radio quasars
detected in very high energy (VHE, E > 100 GeV) gamma rays. Since the
first detection in 2009, despite showing strong variability in the
optical and GeV range, no VHE gamma-ray variability could be claimed
until a moderate 5-fold increase of the VHE gamma-ray flux was
observed in 2015. In May 2016, a major VHE gamma-ray...
M. I. Lopes
(on behalf of LUX Collaboration; University of Coimbra and LIP)
29/08/2018, 16:45
The Large Underground Xenon (LUX) detector was a dual-phase xenon Time Projection Chamber with an active mass of 250 kg searching for Weakly Interacting Massive Particle (WIMP) dark matter via direct detection. It operated at the Sanford Underground Research Facility (SURF) in Lead, South Dakota from 2012 to 2016. LUX has published three previously world leading limits on the spin-independent...
Emma Storm
(University of Amsterdam)
29/08/2018, 16:50
A persistent excess of gamma rays measured with the Fermi-LAT has been found towards the center of the Galaxy, typically referred to as the Galactic Center Excess (GCE). While its existence is well established, its nature and origin are still debated. While a simple but exotic origin for the GCE could be the annihilation of dark matter, other astrophysical origins, such as emission from...
Andreas Rappelt
(Technische Universität München)
29/08/2018, 17:00
The theoretical interpretation of dark matter experiments is hindered by uncertainties of the dark matter density and velocity distribution inside the Solar System. In order to quantify those uncertainties, we present a parameter that characterizes the deviation of the true velocity distribution from the Maxwell-Boltzmann form, and we then determine for different values of this parameter the...
Carlo Romoli
(Max Planck Institute or Nuclear Physics)
29/08/2018, 17:00
The FSRQ 3C 279 (z=0.536) is a well known bright variable blazar.
In recent years it has undergone several luminous outbursts
detected at all wavelengths.
Here we highlight the results of H.E.S.S. observations of two types of
events of different nature
during the year 2017 and in January 2018. The first Target of
Opportunity followed
the external trigger from the ATOM optical telescope...
Dr
Dmitry Malyshev
(Erlangen Center for Astroparticle Physics)
29/08/2018, 17:05
The Fermi bubbles (FBs) are two large lobes observed in gamma rays up to 55 degrees above and below the Galactic center. Although the FBs were discovered 8 years ago, their origin is still unknown. Even the process of production of the gamma rays: leptonic inverse Compton scattering or interactions of hadronic cosmic rays with gas, is not yet known. Answering the questions of the origin of the...
Mr
Lukas Merten
(Ruhr-Universität Bochum)
29/08/2018, 17:06
Experimental observations of Galactic and extragalactic cosmic rays in the last decade challenge
the theoretical description of both the sources and the transport of cosmic rays. The latest version
of the publicly available simulation framework CRPropa 3.2 aims at a consistent solution of the
cosmic-ray transport problem, including the production and propagation of secondary neutrinos...
Dr
Alfredo Tomas Alquezar
(Imperial College London)
29/08/2018, 17:15
LUX-ZEPLIN (LZ) is a second-generation dark matter experiment currently under construction. It will follow LUX in the 1480-m deep Sanford Underground Research Facility in South Dakota, with a projected sensitivity for the spin-independent cross section of $1.6\times10^{-48}~$cm$^{2}$ for a 40 GeV/c$^2$ mass Weakly Interacting Massive Particle (WIMP) after 1000 live-days exposure of a 5.6-tonne...
Prof.
Sergey Troitsky
(INR, Moscow)
29/08/2018, 17:15
Unphysical distance dependence in convex features of deabsorbed blazar spectra (upward breaks), reported in 2014, suggested incorrect model of absorption of E>100 GeV gamma rays due to e+e- pair production on the extragalactic background light (EBL). We present and interpret results of the new study aimed to constrain EBL in the same approach, making use of an updated clean source sample, new...
Ms
Lili Yang
(University of Nova Gorica), Prof.
Soebur Razzaque
(University of Johannesburg)
29/08/2018, 17:20
The Fermi bubbles (FBs) are two giant gamma-ray lobes above and below the Galactic center. Their origin is not clear yet and both hadronic and leptonic models are currently allowed. In the hadronic model, the acceleration of protons and/or nuclei and their subsequent interactions with gas in the bubble volume can produce the observed gamma rays and high-energy neutrinos as counterparts. The...
Chad Bustard
(University of Wisconsin - Madison)
29/08/2018, 17:23
Diffusive shock acceleration (DSA) at supernova remnant (SNR) shock fronts is thought to accelerate galactic cosmic rays (CRs) to energies below the knee, while an extragalactic origin is presumed for CRs with energies beyond the ankle. CRs with energies between $3 \times 10^{15}$ and $10^{18}$ eV, which we dub the ``shin," have an unknown origin. In this talk, I will outline our recent...
Dr
Thomas Lacroix
(Laboratoire Univers et Particules de Montpellier)
29/08/2018, 17:30
In the context of dark matter (DM) searches, it is crucial to quantify and reduce theoretical uncertainties affecting predictions of observables that depend on the DM velocity distribution, including event rates in direct searches, velocity-dependent annihilation rates, and microlensing event rates for DM compact objects. The well-known Eddington inversion formalism for the self-consistent...
Dr
Mikhail Kuznetsov
(INR RAS, Moscow)
29/08/2018, 17:30
The Universe is expected to be opaque for gamma rays with TeV energies. However several distant blazars have been observed in TeV region. One possible solution to this puzzle is to assume that the same sources emit cosmic rays towards the Earth and the gamma rays observed are products of line of sight cosmic ray interactions. We examine viability of this scenario in the context of possible...
Mr
Thomas Edwards
(GRAPPA, University of Amsterdam)
29/08/2018, 17:35
Global properties of the almost one hundred millisecond pulsars (MSPs) detected in gamma-rays by the Fermi Large-Area Telescope remain relatively unknown due to multiple large uncertainties. I present here a extensive Bayesian analysis of both the spatial distribution and luminosity function simultaneously. Distance uncertainties, arising from errors in the parallax measurement or Galactic...
Dr
Humberto Martínez-Huerta
(IFSC - USP)
29/08/2018, 17:40
In this work, the photon horizon including LIV is studied by correcting the pair-production interaction of gamma-ray with the Cosmic Background Light. The derived scenarios are used to predict important changes in the propagation of photons with energy greater than 10 ^ 18 eV. We have computed the GZK photon flux on Earth for several ultra high energy cosmic ray source (UHECR) models and we...
Prof.
Torsten Bringmann
(Oslo University)
29/08/2018, 17:45
We present a radically new version of the widely used DarkSUSY package, which allows to compute the properties of dark matter particles numerically. With DarkSUSY 6 one can accurately predict a large variety of astrophysical signals from dark matter, such as direct detection in low-background counting experiments and indirect detection through antiprotons, antideuterons, gamma-rays and...
Mr
Hassan Abdalla
(North-West University)
29/08/2018, 17:45
At energies approaching the Planck energy scale $10^{19} GeV$, several quantum-gravity theories predict that familiar concepts such as Lorentz (LIV) symmetry can be broken.
Such extreme energies are currently unreachable by experiments on Earth, but for photons traveling over cosmological distances the accumulated deviations from the Lorentz symmetry may be measurable using the Cherenkov...
Michael Kachelriess
(NTNU)
29/08/2018, 17:50
A signal of high-energy extraterrestrial neutrinos from unknown source(s) was recently discovered by the IceCube experiment. Neutrinos are always produced together with γ-rays, but the γ-ray flux from extragalactic sources is suppressed due to attenuation in the intergalactic medium. We report a γ-ray excess at high Galactic latitudes starting at energies 300 GeV in the data of the Fermi...
Joachim Kopp
(University of Mainz & CERN)
30/08/2018, 10:00
We discuss the current status of theoretical and experimental neutrino physics, focusing on ways in which neutrinos can help to answer some of the most fundamental questions in particle physics and astrophysics. Topics covered include neutrino oscillations, neutrino masses, neutrino astronomy, and connections between the neutrino sector and dark matter.
Ralf Kissmann
(Universität Innsbruck)
30/08/2018, 11:00
I will present an overview of recent developments in numerical modelling of CR transport in our Galaxy. Corresponding numerical models aim at reproducing CR spectra and also diffuse gamma-ray emission from the Galaxy. For these numerical models we witness a transition from two-dimensional azimuthally symmetric models to those that use a more realistic description of our Galaxy. Focusing on...
Prof.
Pierre SALATI
(Laboratoire d'Annecy-le-Vieux de Physique Théorique LAPTh @ USMB)
30/08/2018, 11:30
Antimatter cosmic rays have become a fashionable tool to probe for the presence of dark matter particles in the Milky Way. Should these species exist, they would annihilate or decay, hence producing positrons and anti-nuclei which would distort the conventional signals expected at the Earth. But are these backgrounds well known? There’s the rub.
Regardless of the dark matter problem,...
Ralf Ulrich
(Karlsruhe Institute of Technology)
30/08/2018, 14:00
Many limitations in understanding important aspects of hadron collisions become most visible in the forward phase space at colliders. This is where the contributing physics is most soft, however, at the same time the energy transport is by far largest. This is why this region is in particular important for astroparticle physics. The CASTOR calorimeter at CMS has performed a series of...
Dr
Carlos de los Heros
(Uppsala University)
30/08/2018, 14:00
The IceCube Neutrino Observatory at the South Pole is the world's largest neutrino telescope in operation. It instruments a kilometer cube of ice with more than 5000 optical sensors that detect the Cherenkov light emitted by particles produced in neutrino-nucleon interactions. Being sensitive to a wide range of neutrino energies, from a few GeV to PeVs, its physics program is extremely rich....
Philipp Mertsch
(TTK, RWTH Aachen University)
30/08/2018, 14:00
Despite significant progress over more than 100 years, no cosmic ray accelerator has been unambiguously identified as the source of the locally measured flux. High-energy electrons and positrons are of particular relevance in the search for sources as radiative energy losses constrain their propagation to distances of about 1 kpc. At the highest energies, the measured spectrum is dominated and...
Giacomo Graziani
(INFN Firenze)
30/08/2018, 14:15
The LHCb experiment has the unique possibility, among the LHC experiments,
to be operated in fixed target mode using its internal gas target.
The energy scale achievable at the LHC and the excellent detector
capabilities for vertexing, tracking and particle identification allow a
wealth of novel measurements of great interest for cosmic ray physics. In
particular, using a helium...
Silvia Manconi
(University of Turin and INFN Turin)
30/08/2018, 14:17
The inclusive flux of cosmic electrons and positrons is now known with unprecedented precision up to few tens of TeV. Very recent data from AMS-02, DAMPE, CALET, FERMI and HESS suggest that the flux starts deviating from a single power law at TeV energies, with the presence of a break at around 1 TeV. In addition, new stringent upper bounds on the dipole anisotropy of the inclusive flux have...
Dr
Shriharsh Tendulkar
(McGill University)
30/08/2018, 14:20
Fast Radio Bursts (FRBs) are mysterious radio transients that occur at a prodigious rate of $\approx 10^3$ events per day above fluences of 1 Jansky-ms in the entire sky. Arriving from cosmological distances ($\sim$Gpc), FRBs show potential to be novel probes of cosmological parameters, the ionized baryon distribution, and the magnetic fields around and between galaxies. We do not know the...
Dr
Vincent Poireau
(LAPP/CNRS)
30/08/2018, 14:20
In this talk, we present the latest results on dark matter searches using the High Energy Stereoscopic System (H.E.S.S.) located in Namibia. Dark matter is searched for looking for high-energy gamma-ray events in the most promising regions of the sky. Dark matter particles could self-annihilate and produce high-energy gamma rays, either as spectral lines or as continous spectrum. The inner...
Dr
Daniel Kerszberg
(IFAE-BIST)
30/08/2018, 14:34
Multi-TeV cosmic-ray electrons carry unique information about local accelerators because of their severe radiative energy losses and the associated short propagation distances. The very low fluxes and the large background of hadronic cosmic rays however impose severe challenges to both space-born and ground-based measurements. The next generation satellite experiments are just starting to...
Mr
Ido Reiss
(Ben Gurion University of the Negev)
30/08/2018, 14:40
Galaxy clusters are thought to grow by accreting mass through large scale, strong yet elusive, virial shocks. These collisionless shocks are thought to accelerate relativistic electrons, generating a spectrally-flat leptonic virial ring. However, with the exception of a VERITAS signal from the Coma cluster, attempts to detect virial rings have all failed. By stacking and rescaling Fermi-LAT...
Dr
Andrea Vittino
(TTK, RWTH Aachen)
30/08/2018, 14:51
Electrons and positrons play a special role among cosmic ray (CR) species. Most strikingly, their strong energy losses in the Galactic magnetic and radiation fields severely limit their propagation distances. Therefore electrons and positrons offer invaluable insights into the local properties of CR acceleration and propagation. In this talk we present our model for their interstellar spectra...
Dr
Felicia Krauss
(GRAPPA/API, UvA)
30/08/2018, 14:55
PMN J1603−4904 is only the second confirmed young radio galaxy (compact symmetric object) that has been detected with *Fermi*-LAT. These objects, which may transition into larger radio galaxies, are a stepping stone to understanding AGN and jet evolution. It is not clear how they can produce high-energy γ rays. We present multiwavelength observations, including a spectral energy distribution...
Mr
Javier Coronado-Blázquez
(IFT UAM-CSIC)
30/08/2018, 15:00
We perform a search of Dark Matter (DM) subhalo candidates among unassociated catalogued sources present in the most recent Fermi-LAT point-source catalogs (3FGL, 2FHL and 3FHL). These LCDM-predicted DM subhalos are promising candidates for gamma-ray emission from WIMP annihilation in the LAT energy band. Several selection criteria are applied, based on the expected properties of the...
Dr
Mattia DI MAURO
(STANFORD UNIVERSITY)
30/08/2018, 15:08
An excess of cosmic positrons above 10 GeV with respect to the spallation reaction of cosmic rays (CRs) with the interstellar medium has been measured by Pamela, Fermi-LAT and with unprecedented precision by the AMS-02 experiment. Various interpretations have been invoked to interpret this excess, such as production from supernova remnants, pulsar wind nebulae (PWNe) and dark matter. A...
Dr
Tomislav Terzić
(University of Rijeka, Department of Physics)
30/08/2018, 15:10
TON 0599 (z=0.7247) is the latest addition to a limited club of flat spectrum radio quasars (FSRQs) detected in very high energy (VHE, E > 100 GeV) gamma rays. Its redshift makes it the third farthest source, filling the gap in the redshift distribution of the VHE gamma ray emitters. It was detected for the first time with the MAGIC telescopes on 2017/12/15. The observations were triggered by...
Laura Chang
(Princeton University)
30/08/2018, 15:15
The Milky Way halo is the brightest source of dark matter annihilation on the sky. Indeed, the potential strength of the Galactic dark matter signal can supersede that expected from dwarf galaxies and galaxy groups even in regions away from the Inner Galaxy. We present the results of a search for dark matter annihilation in the smooth Milky Way halo for $|b| > 20^\circ$ and $r < 50^\circ$...
Dr
Giovanni Benato
(University of California, Berkeley)
30/08/2018, 15:30
The Cryogenic Underground Observatory for Rare Events (CUORE) is the first bolometric experiment searching for neutrinoless double beta decay that has been able to reach the 1-ton scale. The detector consists of an array of 988 TeO2 crystals arranged in a cylindrical compact structure of 19 towers. The construction of the experiment and, in particular, the installation of all towers in the...
Mr
Christopher Eckner
(University of Nova Gorica)
30/08/2018, 15:30
Revealing the nature of dark matter is one of the most riveting open tasks of modern astronomy and cosmology. To this end, observing and analyzing high-energy gamma-rays provides a promising and highly-effective tool to constrain the properties of dark matter particles.
Being currently in its pre-construction phase, the Cherenkov Telescope Array (CTA) will soon observe the high-energy...
Dr
Raul Monsalve
(McGill University)
30/08/2018, 16:15
I will present the measurement of an absorption feature in the sky-averaged radio spectrum centered at 78 MHz with the EDGES experiment. The measured feature is broadly consistent with the absorption of photons from the microwave background by neutral hydrogen gas in the intergalactic medium (IGM) due to significant star formation about 180 million years after the Big Bang. Despite this...
Lukáš Fajt
(IEAP CTU in Prague)
30/08/2018, 16:15
Baikal-GVD is a next generation, cubic-kilometer scale neutrino telescope which has been constructed since 2015 in the largest and deepest freshwater lake in the world, Lake Baikal. The detector itself is built from independent multi-megaton sub-arrays called clusters whose centers are 300 meters away. Every cluster consists of 8 strings each carrying 36 Optical Modules (OMs) vertically spaced...
Mr
Giovanni Ceribella
(Max-Planck-Institut für Physik)
30/08/2018, 16:15
Pulsars are among the most compact Very High Energy photon sources of the universe, but the physics processes behind their emission are not yet fully understood.
MAGIC, a system of two Imaging Atmospheric Cherenkov Telescopes located at 2200 m a.s.l. on the Canary Island of La Palma (Spain), has pioneered the field of VHE pulsar physics and continues contributing to the advancement of our...
Mr
Arturo Nunez-Castineyra
(Aix Marseille Université, LAM (Laboratoire d’Astrophysique de Marseille))
30/08/2018, 16:20
In the framework of zoom-in cosmological simulations published in Mollitor et al 2015, together with news runs, we compare the phase-space distributions of simulations of Milky Way like Halos with those inferred by the Eddington inversion. This method as presented by Lacroix et al 2018 is able to deduce the phase-space distribution of Dark Matter (DM) at different radii from the mass...
Mr
Ulrich Feindt
(Stockholm University)
30/08/2018, 16:30
The Zwicky Transient Facility (ZTF) has started operating earlier this year and is continuously discovering transients throughout the norther sky. Over the course of its three-year survey we expect to find thousands of supernovae, including 2000 type Ia supernovae at low redshifts (z < 0.1) with high-quality lightcurves needed for determining cosmological distances. Such a sample will be...
Mr
Paul Kin-Hang YEUNG
(University of Hamburg)
30/08/2018, 16:32
The Crab nebula is a bright emitter of non-thermal radiation across the entire
accessible range of wavelengths. The spatial and spectral structures of the synchrotron nebula are well-resolved from radio to hard X-ray emission. The un-pulsed emission at GeV to TeV energies is mostly produced via inverse-Compton scattering of energetic electrons with the synchrotron-emitted photons. The spatial...
Prof.
Francesco Villante
(Università dell'Aquila and INFN-LNGS)
30/08/2018, 16:35
A detailed multi-messenger study of the high-energy emission from the Galactic plane is possible nowadays thanks to the observations provided by gamma and neutrino telescopes. We show the potential of this approach by using the total gamma flux from the galactic plane measured by HESS at 1TeV and in the longitude range −75° < l < 60°. We compare the HESS observational data with expectations...
Dr
Nilanjan Banik
(Leiden University/GRAPPA, University of Amsterdam)
30/08/2018, 16:35
A key prediction of the standard cosmological model -- which relies on the assumption that dark matter is cold, i.e. non-relativistic at the epoch of structure formation -- is the existence of a large number of dark matter substructures on sub-galactic scales. This assumption can be tested by studying the perturbations induced by dark matter substructures on cold stellar streams. Here, we...
Dr
Vivian Poulin
(Johns Hopkins University)
30/08/2018, 16:45
In this talk, I would like to review how the CMB (in particular its temperature and polarization anisotropies) can be used to look for ultra light axion-like particles (ULAs).
Such ULAs are numerous in the axiverse scenario and can play many role in cosmology, from Dark Matter to Dark Energy. Moreover, they have been invoked to solve several recent cosmological tensions. In particular, ULAs...
Dr
Jacco Vink
(University of Amsterdam)
30/08/2018, 16:49
The synchrotron spectrum of the Crab Nebula has long been a mystery:
rather than having one cooling break, there are at least two breaks:
around 1E14 Hz, and around 1E16 Hz. The spectrum cuts off around 1E21 Hz.
The break around 1E14 Hz can be explained by synchrotron cooling, but
the second break is rather enigmatic and various explanations have been
offered, often involving the...
Dr
Camilo Alfredo Garcia Cely
(DESY)
30/08/2018, 16:50
I will present a well-motivated dark matter scenario that naturally predicts
a strong emission of gravitational waves in the Early Universe. Interplay with Higgs physics as well as the corresponding dark matter phenomenology will be discussed.
Joshua Wood
(University of Wisconsin, Madison)
30/08/2018, 16:55
We present a search for neutrino emission from Galactic TeV gamma-ray sources detected by the HAWC Observatory. HAWC serves as an excellent instrument to complement IceCube with its energy range extending to very high energies where we expect neutrinos correlated with the gamma-rays observed by HAWC, assuming that the highest energy photons originate from the decay of pions. Using 8 years of...
Patrick Fitzpatrick
(Center for Theoretical Physics, Massachusetts Institute of Technology)
30/08/2018, 17:00
The robustness of inflation to inhomogeneous initial conditions for matter fields and the spacetime metric is under investigation. If inflationary expansion fails to begin under sufficiently inhomogeneous initial conditions, such that inflation requires fine-tuning of its initial state to occur, then its naturalness is challenged. I will present results for the range of initial conditions...
Dr
Daniele Gaggero
(SISSA, Trieste)
30/08/2018, 17:05
The idea that primordial black holes (PBHs) of O(10) solar mass can account for most of the dark matter has been recently reconsidered after the discovery of gravitational waves from binary-black hole merger events.
I present a significant update of a robust bound on this scenario based on a conservative modeling of the gas accretion and the subsequent radio and X-ray emission originating by...
Dr
Atri Bhattacharya
(University of Liege)
30/08/2018, 17:10
As the IceCube has steadily collected data over the last several years, certain tensions have emerged between observations on one hand and fits obtained to these observations when assuming a single power-law diffuse astrophysical flux of neutrinos on the other; and between fits obtained using different kinds of datasets (HESE vs through-going muons). We analyse whether these tensions may be...
Evan Hall
(Massachusetts Institute of Technology)
30/08/2018, 17:15
The current generation of gravitational-wave detectors have provided a wealth of information from coalescences of binary black holes and binary neutron stars. However, even at design sensitivity these detectors are only able to observe coalescences from the local universe, out to redshifts of a few. In contrast, the next generation of longer and more sensitive gravitational-wave detectors,...
Dr
Tim Linden
(The Ohio State University)
30/08/2018, 17:23
Recent HAWC observations have found extended TeV emission coincident with the Geminga and Monogem pulsars. In this talk, I will show that these detections have significant implications for our understanding of the TeV gamma-ray sky. First, the spectrum and intensity of these TeV Halos indicates that a large fraction of the pulsar spindown energy is efficiently converted into electron-positron...
Thomas gaisser
(university of delaware)
30/08/2018, 17:25
Atmospheric neutrinos are of interest as a beam for the study of neutrino properties and as a foreground in the search for astrophysical neutrinos. An accurate understanding of their flux is important for both. Uncertainties in the flux of atmospheric neutrinos arise from composition and spectrum of the primary cosmic radiation and from imperfect knowledge of hadronic interactions. Both...
Dr
Holger Motz
(Waseda University)
30/08/2018, 17:35
Installed on the ISS in August 2015 and taking data since October of that year, CALET (CALorimetric Electron Telescope) is directly measuring the electron+positron cosmic-ray spectrum up into the TeV-region with fine energy resolution and good proton rejection. The latest published total electron+positron spectrum is analyzed for Dark Matter signatures. Limits on annihilation and decay of Dark...
Dr
Michael Pürrer
(Max Planck Institut für Gravitationsphysik, Potsdam)
30/08/2018, 17:35
In this talk I will summarize the current astrophysical results from searching for binary black hole mergers in data taken from second generation gravitational wave observatories. I will focus on estimates of binary parameters found with Bayesian inference techniques and state-of-the art waveform models which describe the inspiral, merger and ringdown phases of these coalescences. I will...
Dr
Jian Li
(Deutsches Elektronen-Synchrotron (DESY))
30/08/2018, 17:40
MGRO J1908+06 is an unidentified bright TeV source. It has been proposed to be one of the most likely neutrino sources. However, no counterpart of MGRO J1908+06 has been detected at other wavelengths, and its nature remains unknown. PSR J1907+0602 is a 106.6 ms gamma-ray pulsar with high spin down power (∼ 2.8×10^36 erg/s) and is spatially associated with MGRO J1908+06. By analyzing Fermi/LAT...
Tyce DeYoung
(Michigan State University)
30/08/2018, 17:40
Although designed to observe neutrinos from astrophysical sources at TeV-PeV energies, IceCube and its DeepCore in-fill array also observe large numbers of atmospheric neutrinos in the 5-50 GeV range, permitting measurements of the “atmospheric” neutrino mixing parameters in a higher energy range complementary to measurements from long-baseline neutrino beam experiments. As these energies are...
Mr
Michael Korsmeier
(University of Torino)
30/08/2018, 17:50
Cosmic rays are one important tool to study dark matter annihilation in our Galaxy. Recently, a possible hint for dark matter annihilation was found in the antiproton spectrum measured by AMS-02. The potential signal is affected by many theoretical and systematic uncertainties making its validation or exclusion a non-trivial task. The most direct but complementary way to test the dark matter...
Mrs
Monica Seglar Arroyo
(CEA)
30/08/2018, 17:55
In this contribution, the search of high-energy gamma ray emission as electromagnetic counterpart of the binary neutron star merger GW170817 with the H.E.S.S. Imaging Air Cherenkov Telescopes is presented. Observations started 5.3 h after the merger and contained the counterpart SSS17a that was identified several hours later. It stands as the first data obtained by a ground-based pointing...
Dr
Shigeo Kimura
(Pennsylvania State University)
30/08/2018, 18:10
Last year, LIGO-VIRGO collaborations reported detection of the first neutron star merger event, GW170817, which accompanied with observations of electromagnetic counterparts from radio to gamma rays. High-energy gamma rays and neutrinos were not observed. However, the mergers of neutron stars are expected to produce these high-energy particles. In this talk, I will discuss the prospects for...
Dr
Harald Pfeiffer
(Max-Planck-Institute for Gravitational Physics (Albert-Einstein-Institute))
30/08/2018, 19:00
Dr
Carlos Argüelles Delgado
(Massachusetts Institute of Technology (MIT))
31/08/2018, 11:00
The IceCube neutrino observatory has not only discovered the existence of a cosmic neutrino component, but has also made precise measurements of the TeV atmospheric neutrino flux. Using these high-energy atmospheric neutrinos and the astrophysical neutrinos I will present results of searches for new neutrino flavors and interactions. On the former, I will report the status of searches for eV...
Dr
Daniele Gaggero
(GRAPPA, University of Amsterdam)
31/08/2018, 12:00
The extremely accurate charged cosmic-ray data recently provided by the AMS collaboration and the gamma-ray data from Fermi-LAT and other experiments allowed to enter a new era of precision measurements in the CR field, and offer for the first time the unique opportunity to investigate different transport properties in different regions of the Galaxy. I will review the status of the field, the...
Dr
Marco Ajello
(Clemson University)
31/08/2018, 12:15
The light emitted by all galaxies across the history of the Universe is encoded in the intensity of the extragalactic background light (EBL), the diffuse cosmic radiation field at ultraviolet, optical, and infrared wavelengths. The EBL is a source of opacity for high-energy γ rays via the photon-photon interaction (γγ → e+e−), leaving a characteristic attenuation imprint in the spectra of...
Ms
Carlotta Pittori
(INAF-OAR and ASI-SSDC)
31/08/2018, 14:00
We present the results of a systematic search in the AGILE quick-look database for transient gamma-ray sources above 100 MeV that are temporally and spatially coincident with published high-energy neutrino IceCube events.
AGILE is a small scientific mission of the Italian Space Agency (ASI) in cooperation with
INAF, INFN, CIFS, and with the participation of several Italian companies and...
Dr
Oliver Porth
(ITP Frankfurt)
31/08/2018, 14:00
PWN make up the majority of the identified galactic TeV sources and are a key ingredient to understand the high energy sky. In this contribution, I will review recent progress in magnetohydrodynamic and particle transport modeling of PWN, highlighting advances with fully three-dimensional global models. It is now clear that the MHD kink- and Kelvin Helmholtz-type instabilities lead to...
Gabrijela Zaharijas
(Center for astrophysics and cosmology/Un. of Nova Gorica)
31/08/2018, 14:00
Observations of high-energy gamma rays are one of the most promising tools to constrain or reveal the nature of dark matter. During the remarkable ten years of the Fermi satellite mission, the data from its Large Area Telescope (LAT) were used to set constraints on the dark matter cross section to various particle channels which cut well into the theoretically motivated region of the parameter...
Dr
Foteini Oikonomou
(European Southern Observatory)
31/08/2018, 14:00
The Pierre Auger Observatory is the world’s largest cosmic-ray detector, sensitive to cosmic rays with energy exceeding $\sim 10^{17}$ eV. In addition to charged cosmic rays that form the bulk of the cosmic-ray flux at ultra-high energies, Auger is sensitive to ultra-high energy neutral messengers (photons, neutrinos, and neutrons). The latter are particularly exciting as they are expected to...
Lisa Schumacher
(RWTH Aachen)
31/08/2018, 14:15
Cosmic rays were discovered a century ago, however the sources of the ultra-high-energy events remain unidentified.
It is believed that the same environments that accelerate ultra-high-energy cosmic rays (UHECRs) also produce high-energy neutrinos via hadronic interactions.
Two out of three joint analyses of the IceCube Neutrino Observatory, the Pierre Auger Observatory and the Telescope...
Roland Crocker
(Australian National University)
31/08/2018, 14:20
An anomalous, apparently diffuse, gamma-ray signal not readily attributable to known Galactic sources has been found in Fermi space telescope data covering the central ~10 degrees of the Galaxy. This "Galactic Center Gamma-Ray Excess" (GCE) signal has a spectral peak at ~2 GeV and reaches its maximum intensity at the Galactic Centre (GC) from where it falls off as a radial power law ~r^{-2.4}....
Dr
Arjen van Vliet
(DESY Zeuthen)
31/08/2018, 14:30
When ultra-high-energy cosmic rays (UHECRs) travel through the universe they create cosmogenic neutrinos via several interactions. The expected flux at Earth of these cosmogenic neutrinos generally depends on multiple parameters describing the sources and propagation of UHECRs. However, at a neutrino energy of ~1 EeV a 'sweet spot' occurs where this flux only depends strongly on two...
Timur Dzhatdoev
(SINP MSU)
31/08/2018, 14:34
Emission of distant (redshift z>0.1) extragalactic sources in the GeV-TeV energy range may be significantly transformed during the propagation between the source and the observer. So far, the only robust result in this area was the firm establishment of the existence of the \gamma\gamma\rightarrow e^{+}e^{-} pair production process. During the last 8 years, there were many other claims that...
Dr
Vivian Poulin
(Johns Hopkins University)
31/08/2018, 14:40
In this talk, I would like to review how the CMB (in particular its temperature and polarization anisotropies) can be used to perform both direct and indirect detection of DM.
Firstly, I will show the great complementarity between underground direct detection experiment and the CMB in looking for direct scattering between dark and baryonic matter. I will then discuss how the CMB challenges...
Mr
Jonas Heinze
(Desy Zeuthen)
31/08/2018, 14:45
We present a combined fit of the Auger spectrum and composition based on a newly developed code for the extragalactic propagation of cosmic ray nuclei (PriNCe). This very efficient numerical solver of the transport equations allows for scans over large ranges of unknown UHECR source parameters.
Here, we present a study of a generalized source population with three parameters...
Mr
Michele Ronco
(Sapienza University of Rome, INFN, University of Valencia, IFIC)
31/08/2018, 14:51
Some recent studies exposed rather strong statistical evidence of in-vacuo-dispersion-like spectral lags for gamma-ray bursts (GRBs), a linear correlation between time of observation and energy of GRB particles. Those results focused on testing in-vacuo dispersion for the most energetic GRB particles, and in particular only included photons with energy at emission greater than 40 GeV. We here...
Ms
Francesca Capel
(KTH Royal Institute of Technology)
31/08/2018, 15:00
The study of UHECR is challenged by both the rarity of events and the difficulty in modelling their production, propagation and detection. The physics behind these processes is complicated, requiring high-dimensional models which are impossible to fit to data using traditional methods. Whilst non-trivial, it is indeed possible to directly fit realistic, physical models to the UHECR data. The...
Prof.
Dan Hooper
(Fermilab/University of Chicago)
31/08/2018, 15:00
I will review the arguments in favor of either pulsars or annihilating dark matter as the source of the GeV excess observed from the Inner Galaxy. While it is not clear at this time which of these interpretations is correct, I will argue that upcoming observations will likely clarify the situation considerably.
Zeljka Bosnjak
(FER-University of Zagreb)
31/08/2018, 15:08
We use a time-dependent numerical model to calculate the prompt GRB emission (spectra and light curves) in GeV/TeV energy range. The emission is modelled by combining a time-dependent radiative code, solving for the electron and photon distributions, with a dynamical code calculating the evolution of the physical conditions in the shocked regions of the outflow. The microphysics parameters...
Mr
Vikas Joshi
(Max-Planck-Institut für Kernphysik)
31/08/2018, 15:15
The High Altitude Water Cherenkov (HAWC) gamma-ray observatory has been fully operational since March 2015 in central Mexico. Using $\sim$3 years of HAWC data and recently developed energy estimation techniques, now it is possible to study the highest energy sources with their energy-dependent morphology. The unidentified VER J2019+368 is among the highest energy sources and shows significant...
Dr
Marco Chianese
(University of Southampton)
31/08/2018, 15:15
Recent analyses of the diffuse TeV-PeV neutrino flux highlight a tension between different IceCube data samples that strongly suggests a two-component scenario rather than a single steep power-law. In this talk, I show how such a tension is further strengthened once the latest ANTARES (9-year) and IceCube (6-year) data are combined together. Remarkably, both experiments show an excess in the...
Mr
Valentin Decoene
(Institut d'Astrophysique de Paris)
31/08/2018, 15:15
In the context of the recent multi-messenger observation of neutron-star merger GW170817, we examine whether such objects could be sources of ultrahigh energy cosmic rays. At first order, the energetics and the population number is promising to envisage the production of a copious amount of particles, during the first minutes to weeks from the merger. On the other hand, the strong radiative...
Martin Tluczykont
(University of Hamburg)
31/08/2018, 15:25
The Tunka Advanced Instrument for cosmic ray and Gamma ray Astrophysics, TAIGA, aims at accessing the gamma-ray sky in the multi-TeV to PeV energy regime. This energy range is key to spectroscopically resolving the cutoff regime of the - yet to be identified - Galactic cosmic ray Pevatrons. Sensitive gamma-ray observations in this energy range are essential for this task, and require a very...
Matthias Vereecken
(Vrije Universiteit Brussel)
31/08/2018, 15:30
The existence of an astrophysical neutrino flux at TeV to PeV energies has now been firmly established by the IceCube collaboration. However, the sources responsible for this flux have not yet been identified. The most important candidates, steady emitting blazars and transient gamma-ray bursts, favoured on the basis of their high gamma-ray luminosity, are now ruled out as the dominant source...
Emma de Ona Wilhelmi
(CSIC-IEEC)
31/08/2018, 15:30
SNR G24.7+0.6 is a 9.5 kyrs radio and GeV gamma-ray supernova remnant (SNR) evolving in a dense medium. In the GeV regime, SNR G24.7+0.5 shows a hard spectral index which which if extended to very high energies should be easily detected by current Cherenkov telescopes. We observed the field of view of SNR G24.7+0.6 with the MAGIC telescopes. The region shows a complex environment, displaying...
Zhen Cao
(Institute of High Energy Physics)
31/08/2018, 15:42
LHAASO is a complex of air shower detector arrays under construction. With the detection of muons in air shower, the arrays have strong selection power of VEH-UHE gamma rays out of the CR background. Its wide FoV and continuous operation time will provide a survey sensitivity of 10 mini-Crab-unit over the whole northern sky and monitoring for transient phenomena, such as GRB HE-photons. The...
Dr
Jordan Hanson
(Whittier College)
Neutrinos
Talk
Ultra-High Energy (UHE) neutrino (nu) detection via the Askaryan effect in Antarctic ice is a long-time goal of the field of astro-particle physics. The Askaryan effect occurs when a UHE cascade radiates electromagnetic waves. For UHE-nu interactions, the Askaryan signal is expected to be in the radio-frequency (RF) bandwidth, and Antartic ice is a suitable detection medium for such signals....
