52 citations · 333 across the 26 of their papers we have counts for
25 papers · 1 filter
Evidence for a spectral steepening of the gamma-ray emission from the Galactic Center ridge
A. Acharyya, F. Aharonian, H. Ashkar +130
Very-high-energy (VHE) -ray emission detected from the central molecular zone (CMZ) hints at diffusive propagation of cosmic rays (CRs) injected continuously near the Galactic c…
Gamma-Ray Constraints on Heavy Axion-Like-Particle Decays from Fermi-LAT and H.E.S.S. Blazar Spectra
A. Acharyya, F. Aharonian, M. Backes +117
The propagation of very-high-energy (VHE; GeV) gamma rays from extragalactic sources is affected by interactions with photons of the extragalactic background light (…
Search for long-term variability of HESS J1745-290
H. E. S. S. Collaboration, :, A. Acharyya +116
At the center of our Galaxy lies the bright γ-ray point-like source HESS J1745-290, which is compatible in position with Sgr A star, although an association between the two remains…
Curious Case of CGRaBS J0211+1051: Observational Evidence of Lepto-Hadronic Origin of High-Energy Emission?
Sunil Chandra, Pankaj Kushwaha, Pranjupriya Goswami +1
We present an extensive analysis of the multi-wavelength data of the low-synchrotron-peaked BL Lac object CGRaBS J0211+1051, which has been gathered over more than ten years with m…
The variety of extreme blazars in the AstroSat view
Pranjupriya Goswami, Michael Zacharias, Andreas Zech +3
Extreme blazars have exceptionally hard intrinsic X-ray/TeV spectra and extreme peak energies in their spectral energy distribution (SED). Observational evidence suggests that the…
Discovery of a Radiation Component from the Vela Pulsar Reaching 20 Teraelectronvolts
The H. E. S. S. Collaboration, :, F. Aharonian +178
Gamma-ray observations have established energetic isolated pulsars as outstanding particle accelerators and antimatter factories in the Galaxy. There is, however, no consensus rega…
Gamma-ray detection of newly discovered Ancora SNR: G288.8-6.3
Christopher Burger-Scheidlin, Robert Brose, Jonathan Mackey +5
The supernova remnant (SNR) G288.8-6.3 was recently discovered as a faint radio shell at large Galactic latitude using observations with ASKAP in the EMU survey. Here, we make the…
Joint searches by FACT, H.E.S.S., MAGIC and VERITAS for VHE gamma-ray emission associated with neutrinos detected by IceCube
Fabian Schüssler, Halim Ashkar, Elisa Bernardini +11
The sources of the astrophysical flux of high-energy neutrinos detected by IceCube are still largely unknown, but searches for temporal and spatial correlation between neutrinos an…
The peculiar new state of the blazar PKS 1510-089
H. M. Schutte, M. Zacharias, M. Böttcher +4
Contemporaneous multiwavelength observations with H.E.S.S., SALT, Fermi-LAT, Swift, and ATOM show that the blazar PKS 1510-089 suffered a significant decrease in its optical flux,…
Joint H.E.S.S. and Fermi-LAT analysis of the region around PSR J1813-1749
T. Wach, A. M. W. Mitchell, V. Joshi +1
HESS J1813-178 is one of the brightest sources detected during the first HESS Galactic Plane survey. The compact source, also detected by MAGIC, is believed to be a pulsar wind neb…
Modelling of highly extended Gamma-ray emission around the Geminga Pulsar as detected with H.E.S.S
A. M. W. Mitchell, S. Caroff
Geminga is an enigmatic radio-quiet gamma-ray pulsar located at a mere 250 pc distance from Earth. Extended very-high-energy gamma-ray emission around the pulsar has been detected…
Multiwavelength Observations of the Blazar PKS~0735+178 in Spatial and Temporal Coincidence with an Astrophysical Neutrino Candidate IceCube-211208A
M. Pohl, K. Mori
We report on multiwavelength target-of-opportunity observations of the blazar PKS 0735+178, located 2.2 degrees away from the best-fit position of the IceCube neutrino event 211208…
The vanishing of the primary emission region in PKS 1510-089
F. Aharonian, F. Ait Benkhali, J. Aschersleben +152
In July 2021, PKS 1510-089 exhibited a significant flux drop in the high-energy gamma-ray (by a factor 10) and optical (by a factor 5) bands and remained in this low state througho…
Multiwavelength Observations of the Blazar PKS 0735+178 in Spatial and Temporal Coincidence with an Astrophysical Neutrino Candidate IceCube-211208A
A. Acharyya, C. B. Adams, A. Archer +207
We report on multiwavelength target-of-opportunity observations of the blazar PKS 0735+178, located 2.2 away from the best-fit position of the IceCube neutrino event IceCub…
Constraints on the intergalactic magnetic field using Fermi-LAT and H.E.S.S. blazar observations
H. E. S. S., Fermi-LAT Collaborations, : +134
Magnetic fields in galaxies and galaxy clusters are believed to be the result of the amplification of intergalactic seed fields during the formation of large-scale structures in th…
Constraining the cosmic-ray pressure in the inner Virgo Cluster using H.E.S.S. observations of M 87
H. E. S. S. Collaboration, :, F. Aharonian +160
The origin of the gamma-ray emission from M87 is currently a matter of debate. This work aims to localize the VHE (100 GeV-100 TeV) gamma-ray emission from M87 and probe a potentia…
Detection of extended gamma-ray emission around the Geminga pulsar with H.E.S.S
H. E. S. S. Collaboration, :, F. Aharonian +165
Geminga is an enigmatic radio-quiet gamma-ray pulsar located at a mere 250 pc distance from Earth. Extended very-high-energy gamma-ray emission around the pulsar was discovered by…
H.E.S.S. follow-up observations of GRB221009A
H. E. S. S. Collaboration, :, F. Aharonian +159
GRB221009A is the brightest gamma-ray burst ever detected. To probe the very-high-energy (VHE, \!100 GeV) emission, the High Energy Stereoscopic System (H.E.S.S.) began observat…
HESS J1809193: a halo of escaped electrons around a pulsar wind nebula?
H. E. S. S. Collaboration, :, F. Aharonian +151
Context. HESS J1809193 is an unassociated very-high-energy -ray source located on the Galactic plane. While it has been connected to the nebula of the energetic pulsar PSR J1…
Gamma-ray observations of MAXI J1820+070 during the 2018 outburst
H. Abe, S. Abe, V. A. Acciari +439
MAXI J1820+070 is a low-mass X-ray binary with a black hole as a compact object. This binary underwent an exceptionally bright X-ray outburst from March to October 2018, showing ev…
A deep spectromorphological study of the -ray emission surrounding the young massive stellar cluster Westerlund 1
F. Aharonian, H. Ashkar, M. Backes +156
Young massive stellar clusters are extreme environments and potentially provide the means for efficient particle acceleration. Indeed, they are increasingly considered as being res…
X-ray Observations of 1ES 1959+650 in its high activity state in 2016-2017 with AstroSat and Swift
Sunil Chandra, Markus Boettcher, Pranjupriya Goswami +6
We present a comprehensive multi-frequency study of the HBL 1ES 1959+650 using data from various facilities during the period 2016-2017, including X-ray data from {\it AstroSat} an…
Unfolding the X-ray Spectral Curvature of Mkn 421 for Further Clues
Pranjupriya Goswami, Sunder Sahayanathan, Atreyee Sinha +1
The X-ray observations of Mkn 421 show significant spectral curvature that can be reproduced by a log-parabola function. The spectra can also be fitted by an analytical model consi…
Unravelling the unusually curved X-ray spectrum of RGB J0710+591 using AstroSat observations
Pranjupriya Goswami, Atreyee Sinha, Sunil Chandra +7
We report the analysis of simultaneous multi-wavelength data of the high energy peaked blazar RGB J0710+591 from the LAXPC, SXT and UVIT instruments on-board AstroSat. The wide ban…