Showing 2019 · astro-ph.HEShow all

26 papers · 2 filters

astro-ph.HE2019★ 18 cited

Simultaneous observations of the blazar PKS2155-304 from Ultra-Violet to TeV energies

H. E. S. S., Fermi, NuSTAR collaborations

The results of the first ever contemporaneous multi-wavelength observation campaign on the BL Lac object PKS2155-304 involving Swift, NuSTAR, Fermi-LAT and H.E.S.S. are reported. T…

astro-ph.HE2019★ 21 cited

The BAT AGN Spectroscopic Survey -- XVIII. Searching for Supermassive Black Hole Binaries in the X-rays

Tingting Liu, Michael Koss, Laura Blecha +15

Theory predicts that a supermassive black hole binary (SMBHB) could be observed as a luminous active galactic nucleus (AGN) that periodically varies on the order of its orbital tim…

astro-ph.HE2019★ 7 cited

The Mystery of Photometric Twins DES17X1boj and DES16E2bjy

M. Pursiainen, C. Gutierrez, P. Wiseman +80

We present an analysis of DES17X1boj and DES16E2bjy, two peculiar transients discovered by the Dark Energy Survey (DES). They exhibit nearly identical double-peaked light curves wh…

astro-ph.HE2019★ 10 cited

Bright gamma-ray flares observed in GRB131108A

Donggeun Tak, Z. Lucas Uhm, Bing Zhang

GRB 131108A is a bright long Gamma-Ray Burst (GRB) detected by the Large Area Telescope and the Gamma-ray Burst Monitor on board the Fermi Gamma-ray Space Telescope. Dedicated temp…

astro-ph.HE2019★ 41 cited

Observation of Radar Echoes From High-Energy Particle Cascades

S. Prohira, K. D. de Vries, P. Allison +15

We report the observation of radar echoes from the ionization trails of high-energy particle cascades. These data were taken at the SLAC National Accelerator Laboratory, where the…

astro-ph.HE2019★ 8 cited

Multiple Components in the Broadband -ray Emission of the Short GRB 160709A

Donggeun Tak, Sylvain Guiriec, Z. Lucas Uhm +3

GRB 160709A is one of the few bright short gamma-ray bursts detected by both the Gamma-ray Burst Monitor and the Large Area Telescope on board the - $Te…

astro-ph.HE2019★ 30 cited

Closure relations of Gamma Ray Bursts in high energy emission

Donggeun Tak, Nicola Omodei, Z. Lucas Uhm +3

The synchrotron external shock model predicts the evolution of the spectral () and temporal () indices during the gamma-ray burst (GRB) afterglow for different environmental…

astro-ph.HE2019★ 11 cited

An X-ray Detection of Star Formation In a Highly Magnified Giant Arc

M. B. Bayliss, M. McDonald, K. Sharon +19

In the past decade, our understanding of how stars and galaxies formed during the first 5 billion years after the Big Bang has been revolutionized by observations that leverage gra…

astro-ph.HE2019★ 55 cited

Spikey: Self-Lensing Flares from Eccentric SMBH Binaries

Betty X. Hu, Daniel J. D'Orazio, Zoltan Haiman +4

We examine the light curves of two quasars, motivated by recent suggestions that a supermassive black hole binary (SMBHB) can exhibit sharp lensing spikes. We model the variability…

astro-ph.HE2019★ 69 cited

Fermi and Swift Observations of GRB 190114C: Tracing the Evolution of High-Energy Emission from Prompt to Afterglow

M. Ajello, M. Arimoto, M. Axelsson +147

We report on the observations of gamma-ray burst (GRB) 190114C by the Fermi Gamma-ray Space Telescope and the Neil Gehrels Swift Observatory. The early-time observations reveal mul…

astro-ph.HE2019★ 2 cited

Testing cosmology and fundamental physics with the Cherenkov Telescope Array

H. Martínez-Huerta, J. Biteau, J. Lefaucheur +3

The Cherenkov Telescope Array (CTA) is the next generation ground-based observatory for -ray astronomy at energies above 30 GeV. Thanks to its unique capabilities, CTA observati…

astro-ph.HE2019★ 15 cited

A DECam Search for Explosive Optical Transients Associated with IceCube Neutrinos

R. Morgan, K. Bechtol, R. Kessler +65

In this work, we investigate the likelihood of association between realtime, TeV-PeV energy neutrino alerts from IceCube and optical counterparts in the form of core-collapse super…

astro-ph.HE2019★ 255 cited

A decade of Gamma-Ray Bursts observed by -LAT: The 2 GRB catalog

M. Axelsson, E. Bissaldi, N. Omodei +1

The Large Area Telescope (LAT) aboard the spacecraft routinely observes high-energy emission from gamma-ray bursts (GRBs). Here we present the second catalog of LAT-detecte…

astro-ph.HE2019★ 78 cited

Suppressed effective viscosity in the bulk intergalactic plasma

I. Zhuravleva, E. Churazov, A. A. Schekochihin +3

Transport properties, such as viscosity and thermal conduction, of the hot intergalactic plasma in clusters of galaxies, are largely unknown. While for laboratory plasmas these cha…

astro-ph.HE2019★ 47 cited

Constraints on the emission region of 3C 279 during strong flares in 2014 and 2015 through VHE gamma-ray observations with H.E.S.S

H. E. S. S. Collaboration, H. Abdalla, R. Adam +224

The flat spectrum radio quasar 3C 279 is known to exhibit pronounced variability in the high-energy (MeVGeV) -ray band, which is continuously monitored with Fer…

astro-ph.HE2019★ 15 cited

A NuSTAR view of powerful gamma-ray loud blazars

G. Ghisellini, M. L. Perri, G. Costamante +6

We observed with the NuSTAR satellite 3 blazars at z>2, detected in gamma-rays by Fermi/LAT and in the soft X-rays, but not yet observed above 10 keV. The flux and slope of their X…

astro-ph.HE2019★ 364 cited

The Fourth Catalog of Active Galactic Nuclei Detected by the Fermi Large Area Telescope

LAT collaboration

The fourth catalog of active galactic nuclei (AGNs) detected by the Fermi Gamma-ray Space Telescope Large Area Telescope (4LAC) between 2008 August 4 and 2016 August 2 contains 286…

astro-ph.HE2019★ 33 cited

Finding the remnants of the Milky Way's last neutron star mergers

Meng-Ru Wu, Projjwal Banerjee, Brian D. Metzger +6

The discovery of a binary neutron star merger (NSM) through both its gravitational wave and electromagnetic emission has revealed these events to be key sites of r-process nucleosy…

astro-ph.HE2019★ 36 cited

Search for -ray emission from dark matter particle interactions from Andromeda and Triangulum Galaxies with the Fermi Large Area Telescope

Mattia Di Mauro, Xian Hou, Christopher Eckner +2

The Andromeda (M31) and Triangulum (M33) galaxies are the closest Local Group galaxies to the Milky Way, being only 785 and 870 kpc away. These two galaxies provide an independent…

astro-ph.HE2019

Intra-day variability of three Seyfert Galaxies measured with XMM-Newton

Ashutosh Tripathi, Paul J. Wiita, Alok C. Gupta +2

We present and analyze the variability of three Seyfert galaxies on intra-day timescales. We have analyzed in a uniform manner the 38 longest ( ks) observations made for NGC…

astro-ph.HE2019★ 102 cited

Constraints on the ultra-high energy cosmic neutrino flux from the fourth flight of ANITA

P. W. Gorham, P. Allison, O. Banerjee +57

The ANtarctic Impulsive Transient Antenna (ANITA) NASA long-duration balloon payload completed its fourth flight in December 2016, after 28 days of flight time. ANITA is sensitive…

astro-ph.HE2019★ 1.4k cited

Fermi Large Area Telescope Fourth Source Catalog

LAT collaboration

We present the fourth Fermi Large Area Telescope catalog (4FGL) of gamma-ray sources. Based on the first eight years of science data from the Fermi Gamma-ray Space Telescope missio…

astro-ph.HE2019★ 127 cited

Characterizing the Gamma-Ray Variability of the Brightest Flat Spectrum Radio Quasars Observed with the Fermi LAT

Manuel Meyer, Jeffrey D. Scargle, Roger D. Blandford

Almost 10 yr of -ray observations with the Fermi Large Area Telescope (LAT) have revealed extreme -ray outbursts from flat spectrum radio quasars (FSRQs), temporarily making…

astro-ph.HE2019★ 17 cited

Identifying the 3FHL catalog: I. Archival Swift Observations and Source Classification

Amanpreet Kaur, Marco Ajello, Stefano Marchesi +1

We present the results of an identification campaign of unassociated sources from the Fermi Large Area Telescope 3FHL catalog. Out of 200 unidentified sources, we selected 110 sour…