Search for TeV Gamma-ray Emission from GRB 100621A, an extremely bright GRB in X-rays, with H.E.S.S.
The long gamma-ray burst (GRB) 100621A, at the time the brightest X-ray transient ever detected by Swift-XRT in the 0.3–10 keV range, has been observed with the H.E.S.S. imaging air Cherenkov telescope array, sensitive…
Flux upper limits for 47 AGN observed with H.E.S.S. in 2004−2011
Context. About 40% of the observation time of the High Energy Stereoscopic System (H.E.S.S.) is dedicated to studying active galactic nuclei (AGN), with the aim of increasing the sample of known extragalactic very-high-energy (VHE,…
Search for extended γ-ray emission around AGN with H.E.S.S. and Fermi-LAT
Context. Very-high-energy (VHE; E > 100 GeV) γ-ray emission from blazars inevitably gives rise to electron-positron pair production through the interaction of these γ-rays with the extragalactic background light (EBL). Depending on the magnetic fields in the…
HESS J1640−465 – an exceptionally luminous TeV γ-ray supernova remnant
The results of follow-up observations of the TeV γ-ray source HESS J1640−465 from 2004 to 2011 with the High Energy Stereoscopic System (HESS) are reported in this work. The spectrum is well described by…
H.E.S.S. observations of the Crab during its March 2013 GeV gamma-ray flare
Context. On March 4, 2013 the Fermi-LAT and AGILE reported a flare from the direction of the Crab nebula in which the high-energy (HE; E > 100 MeV) flux was six times above its quiescent level.…
HESS J1818–154, a new composite supernova remnant discovered in TeV gamma rays and X-rays
Composite supernova remnants (SNRs) constitute a small subclass of the remnants of massive stellar explosions where non-thermal radiation is observed from both the expanding shell-like shock front and from a pulsar wind nebula (PWN)…
Long-term TeV and X-Ray Observations of the Gamma-Ray Binary HESS J0632+057
HESS J0632+057 is the only gamma-ray binary known so far whose position in the sky allows observations with ground-based observatories in both the northern and southern hemispheres. Here we report on long-term observations of…
Discovery of very high energy γ-ray emission from the BL Lacertae object PKS 0301−243 with H.E.S.S.
The active galactic nucleus PKS 0301−243 (z = 0.266) is a high-synchrotron-peaked BL Lac object that is detected at high energies (HE, 100 MeV <E < 100 GeV) by Fermi/LAT. This paper reports on the discovery of PKS 0301−243 at very…
Constraints on axionlike particles with H.E.S.S. from the irregularity of the PKS 2155–304 energy spectrum
Axionlike particles (ALPs) are hypothetical light (sub-eV) bosons predicted in some extensions of the Standard Model of particle physics. In astrophysical environments comprising high-energy gamma rays and turbulent magnetic fields, the existence of ALPs…
HESS and Fermi-LAT discovery of γ-rays from the blazar 1ES 1312−423
A deep observation campaign carried out by the High Energy Stereoscopic System (HESS) on Centaurus A enabled the discovery of γ-rays from the blazar 1ES 1312−423, 2° away from the radio galaxy. With a differential…
