27-31 August 2018
LVH, Luisenstraße 58, 10117 Berlin
Europe/Berlin timezone
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Extragalactic Science

Place

Location: LVH, Luisenstraße 58, 10117 Berlin
Address: LANGENBECK VIRCHOW HAUS Luisenstraße 58, 10117 Berlin
Date: from 27 Aug 16:15 to 30 Aug 15:25

Description

Chair 1: Tova Yoast-Hull | Chair 2: Günter Sigl | Chair 3: Shigeo Kimura

Conveners

  • 27 Aug 16:15 - 6:00 PM 1
    • Dr. MATTIA, DI MAURO (Stanford University)
    • Yoast-Hull, Tova (Canadian Institute for Theoretical Astrophysics)
    • Prof. Ioka, Kunihito (Yukawa Institute for Theoretical Physics, Kyoto University)
    • Prof. Sigl, Guenter (University of Hamburg)
  • 29 Aug 16:15 - 6:00 PM 2
    • Dr. MATTIA, DI MAURO (Stanford University)
    • Yoast-Hull, Tova (Canadian Institute for Theoretical Astrophysics)
    • Prof. Ioka, Kunihito (Yukawa Institute for Theoretical Physics, Kyoto University)
    • Prof. Sigl, Guenter (University of Hamburg)
  • 30 Aug 14:00 - 3:25 PM 3
    • Dr. MATTIA, DI MAURO (Stanford University)
    • Yoast-Hull, Tova (Canadian Institute for Theoretical Astrophysics)
    • Prof. Ioka, Kunihito (Yukawa Institute for Theoretical Physics, Kyoto University)
    • Prof. Sigl, Guenter (University of Hamburg)

Timetable | Contribution List

Displaying 18 contributions out of 18
Type: Talk Session: Extragalactic Science
Track: Extragalactic
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 origins ... More
Presented by Dr. Shriharsh TENDULKAR on 30/8/2018 at 12:20
Type: Talk Session: Extragalactic Science
Track: Extragalactic
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 eviden ... More
Presented by Dr. Manuel MEYER on 29/8/2018 at 14:15
Type: Talk Session: Extragalactic Science
Track: Extragalactic
Due to the large amounts of energy they release, the luminous transients called Gamma-Ray Bursts (GRBs) are of great interest for high energy astroparticle physics. In the fireball internal shock scenario, the prompt high energy emission is generated in collisions between regions of the jet with different Lorentz factors. However, the classical internal shock model faces several difficult ... More
Presented by Annika RUDOLPH on 27/8/2018 at 15:10
Type: Talk Session: Extragalactic Science
Track: Extragalactic
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 data a ... More
Presented by Mr. Ido REISS on 30/8/2018 at 12:40
Type: Talk Session: Extragalactic Science
Track: Extragalactic
Electromagnetic cascading of TeV-band gamma-ray emission from distant blazars is a means to investigate the amplitude of magnetic field in the voids of intergalactic space. The flux of cascade emission from some objects is weaker than it should be, leaving two interpretation. The magnetic field may be strong enough to deflect the electron-positron pairs out of the line of sight. Alternatively plas ... More
Presented by Martin POHL on 30/8/2018 at 12:00
Type: Talk Session: Extragalactic Science
Track: Extragalactic
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 knowledg ... More
Presented by Rafael ALVES BATISTA on 27/8/2018 at 14:15
Type: Talk Session: Extragalactic Science
Track: Extragalactic
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 hard ... More
Presented by Dr. Tomislav TERZIĆ on 30/8/2018 at 13:10
Type: Talk Session: Extragalactic Science
Track: Extragalactic
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 (S ... More
Presented by Dr. Felicia KRAUSS on 30/8/2018 at 12:55
Type: Talk Session: Extragalactic Science
Track: Extragalactic
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 that ... More
Presented by Carlo ROMOLI on 29/8/2018 at 15:00
Type: Talk Session: Extragalactic Science
Track: Extragalactic
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 fla ... More
Presented by Dr. Julian SITAREK on 29/8/2018 at 14:45
Type: Talk Session: Extragalactic Science
Track: Extragalactic
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. O ... More
Presented by Dr. Jacek NIEMIEC on 27/8/2018 at 14:55
Type: Talk Session: Extragalactic Science
Track: Extragalactic
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 Telesco ... More
Presented by Mr. Hassan ABDALLA on 29/8/2018 at 15:45
Type: Talk Session: Extragalactic Science
Track: Extragalactic
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 gamm ... More
Presented by Prof. Sergey TROITSKY on 29/8/2018 at 15:15
Type: Talk Session: Extragalactic Science
Track: Extragalactic
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 sour ... More
Presented by Dr. Michael ZACHARIAS on 29/8/2018 at 14:30
Type: Talk Session: Extragalactic Science
Track: Extragalactic
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 usi ... More
Presented by Mr. Shotaro YAMASAKI on 27/8/2018 at 15:45
Type: Talk Session: Extragalactic Science
Track: Extragalactic
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 energ ... More
Presented by Dr. Monica VAZQUEZ ACOSTA on 27/8/2018 at 14:35
Type: Talk Session: Extragalactic Science
Track: Extragalactic
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 ont ... More
Presented by Dr. Tomohisa KAWASHIMA on 27/8/2018 at 15:25
Type: Talk Session: Extragalactic Science
Track: Extragalactic
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 cosmic ... More
Presented by Dr. Mikhail KUZNETSOV on 29/8/2018 at 15:30
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