10 papers
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…
Constraining cosmological parameters from very-high-energy -ray attenuation in blazar spectra: Bayesian inference and systematic uncertainties
Patryk Liniewicz, Emmanuel Moulin
Very-high-energy rays from active galactic nuclei are attenuated through pair production on the extragalactic background light (EBL), providing a probe of cosmic expansion. We…
Broad-band Spectral Modeling of Large-Scale X-ray Jets in High-Redshift Quasars: An MHD-Informed Approach
Patryk Liniewicz, Łukasz Stawarz, C. C. Cheung +2
We present a systematic spectral analysis of kiloparsec-scale jets in high-redshift quasars, modeling their radio-to-X-ray emission as synchrotron radiation and inverse-comptonizat…
Broadband multiwavelength properties of the archetypal blazar 3C 279 during the 2017 Event Horizon Telescope campaign
G. Principe, J. C. Algaba, E. Aviano +529
The archetypal blazar 3C 279 hosts a prominent relativistic jet and exhibits strong broadband variability across the electromagnetic spectrum. In April 2017, the Event Horizon Tele…
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…
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…
The second H.E.S.S. gamma-ray burst catalogue: 15 years of observations with the H.E.S.S. telescopes
A. Acharyya, F. Aharonian, C. Arcaro +143
Recent observational efforts using imaging atmospheric Cherenkov telescopes (IACTs) have led to firm detections of very-high-energy (VHE) signals from bright gamma-ray bursts (GRBs…
H.E.S.S. detection of the PSR J0855-4644 nebula
F. Aharonian, H. Ashkar, M. Backes +131
HESS J0852-463 is a TeV γ-ray source located in the Galactic plane. The region consists of a supernova remnant (SNR, RX J0852.0-4622) with a shell-like morphology, commonly referre…
Constraining the nature of the most extreme Galactic particle accelerator. H.E.S.S. observations of the microquasar V4641 Sgr
A. Acharyya, F. Aharonian, H. Ashkar +131
Microquasars have emerged as promising candidates to explain the cosmic-ray flux at petaelectronvolt energies. LHAASO observations revealed V4641~Sgr as the most extreme example so…