8 papers
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…
H.E.S.S. observations of composite Seyfert-starburst galaxies
H. E. S. S. Collaboration, A. Acharyya, F. Aharonian +119
Context: Composite galaxies that contain both Seyfert and starburst components may produce very high-energy (VHE; >100 GeV) gamma-ray emission at a wide range of spatial scales, fr…
Scrutinizing the 2020 multiwavelength outburst of PKS 0903-57 through observations with H.E.S.S
A. Acharyya, F. Aharonian, F. Ait Benkhali +138
The blazar PKS 0903-57 has recently been classified as a flat spectrum radio quasar at a redshift of . In March and April 2020, Fermi-LAT and AGILE reported tremendous ac…
A precessing jet from a supermassive black hole: multi-wavelength observations of S5 1044+71
M. Cerruti, P. A. Duverne, G. Ganesaratnam +3
The bright gamma-ray blazar S5 1044+71 has been identified as showing very significant quasi-periodic oscillations in the Fermi-LAT data in recent studies, with a periodicity of ab…
HEGS : Revisiting a decade of H.E.S.S. extragalactic observations
François Brun, David Sanchez, Andrew M. Taylor +2
During its first phase, from 2004 up to the end of 2012, the H.E.S.S. (High Energy Stereoscopic System) experiment observed the extragalactic skies for more than 2700 hours. These…
Simulations of high-energy neutrino emissions from blazars with the LeHa-Paris code
Francesco Carenini, Matteo Cerruti
The identification of astrophysical sources responsible for high-energy cosmic neutrinos has long been a challenge. A significant milestone was achieved with the blazar TXS 0506+05…