Discovery of VHE γ-rays from Centaurus A

摘要

Centaurus A is the closest active radio galaxy. Its_ proximity enables unique studies of the processes in relativistic jets and near supermassive black holes. Centaurus A has been intensively studied in many wavelength band, and has also been discussed as a possible site for UHECR acceleration. Here, report the discovery of weak very-high energy Υ-ray emission from Centaurus A with the H.E.S.S. Cherenkov telescope array. The discovery of Centaurus A, together with the detection of M 87, establishes radio galaxies - i.e. AGs with only weak relativistic beaming - as sources of VHE gamma-rays. The implications of these results on the emission site and on the different models available will be discussed.