Related papers: Extragalactic Observations with HESS: Past and Fut…
The recent addition of the 28 m Cherenkov telescope (CT5) to the H.E.S.S. array extended the experiment's sensitivity towards low energies. The lowest energy threshold is obtained using monoscopic observations with CT5, providing access to…
Blazars are the most abundant class of known extragalactic very-high-energy (VHE, E>100 GeV) gamma-ray sources. However, one of the biggest difficulties in investigating their VHE emission resides in their limited number, since less than 60…
The High Energy Stereoscopic System (H.E.S.S.) is an array of five imaging atmospheric Cherenkov telescopes (IACTs) to study gamma-ray emission from astrophysical objects in the Southern hemisphere. It is the only hybrid array of IACTs,…
The H.E.S.S. high-energy gamma-ray observatory is member of the Virgo/LIGO electromagnetic follow-up effort since early 2014. Its capability for transient follow-up studies benefits from its large field of view, rapid response time and high…
In the current multi-messenger astronomy era, it is important that information about joint gravitational wave (GW) and electromagnetic (EM) observations through short gamma-ray burst (sGRBs) remains easily accessible. The possibility for…
The addition of a 28 m Cherenkov telescope (CT5) to the H.E.S.S. array extended the experiment's sensitivity to lower energies, providing new opportunities for studies of Active Galactic Nuclei (AGNs) with soft intrinsic spectra and at high…
Gamma-ray burst astronomy has undergone a revolution in the last three years, spurred by the discovery of fading long-wavelength counterparts. We now know that at least the long duration GRBs lie at cosmological distances with estimated…
We present the discovery of two very-high-energy gamma-ray sources in an ongoing systematic search for emission above 100 GeV from pulsar wind nebulae in survey data from the H.E.S.S. telescope array. Imaging Atmospheric Cherenkov…
The imprint of cosmic backgrounds in the gamma ray spectra of blazars has recently been detected by H.E.S.S. and Fermi-LAT, opening the way to studies of gamma-ray propagation on cosmological scales. This proceeding discusses the current…
Several gamma-ray binaries have been recently detected by the High-Energy Stereoscopy Array (H.E.S.S.) and the Major Atmospheric Imaging Cerenkov (MAGIC) telescope. In two cases, their nature is unknown, since a final observational feature…
With the recent advances made by Cherenkov telescopes such as H.E.S.S., the field of very high-energy (VHE) gamma-ray astronomy has recently entered a new era in which for the first time populations of Galactic sources such as e.g. Pulsar…
Herschel will represent a breakthrough in the study of nearby gas-rich and gas-poor galaxies, as it will for the first time permit imaging photometric and spectroscopic observations of their ISM in the FIR-submm wavelength range. The…
The H.E.S.S. experiment entered its phase II with the addition of a new, large telescope named CT 5 that was added to the centre of the existing array of four smaller telescopes. The new telescope is able to detect fainter air showers due…
The High Energy Stereoscopic System (H.E.S.S.) started observing the extremely powerful long-duration gamma-ray burst, GRB 221009A, after 53 hours of the triggering event. The H.E.S.S. collaboration carried out observations on the 11, 12,…
The study of the universe at energies above 100 GeV is a relatively new and exciting field. The current generation of pointed instruments have detected TeV gamma rays from at least 10 sources and the next generation of detectors promises a…
After the first successful LHC run in 2010-2012, plans are actively advancing for a series of upgrades leading eventually to about above times the design-luminosity in about ten years. The larger luminosity will allow to perform precise…
This work intends to provide a brief summary of some of the Galactic science issues for the next generation of very high energy (VHE) instruments. The latter is here generically understood, as an instrument or set of instruments providing…
The full reionization of intergalactic helium was a major event in the history of the IGM, and UV observations of the He II Gunn-Peterson trough allow us to characterize the end of this process at z~3. Due to intervening hydrogen…
The H.E.S.S. array of imaging Cherenkov telescopes has discovered a number of previously unknown gamma-ray sources in the very high energy (VHE) domain above 100 GeV. The good angular resolution of H.E.S.S. (~0.1 degree per event), as well…
Diffuse $\gamma$-ray emission is the most prominent observable signature of celestial cosmic-ray interactions at high energies. While already being investigated at GeV energies over several decades, assessments of diffuse $\gamma$-ray…