Dirk Lennarz Max-Planck-Institut für Kernphysik

Search for Very-High-Energy Gamma-Ray Emission from GRB100621A with H.E.S.S. (pdf)

The origin of gamma-ray bursts (GRBs) and their internal acceleration mechanisms are among the most enigmatic questions in contemporary astrophysics. GRBs are predicted to emit very high energy (VHE, $>100$ GeV) $\gamma$-rays due to ultra-relativistic shock acceleration and the detection of such radiation would give important insights into the acceleration and radiation processes at work. The H.E.S.S. imaging Cherenkov telescope array, detecting VHE radiation, has observed the long GRB 100621A, the brightest X-ray source ever detected by the \emph{Swift} satellite in the keV range. Due to its relatively small redshift of $\sim0.5$, the favourable position in the southern sky and the relatively short follow-up time this GRB is within reach of the H.E.S.S. instrument. The analysis of the H.E.S.S. data is presented in this contribution.