Discovery of VHE gamma-rays from Centaurus A
/ Authors
M. Raue, J. Lenain, F. Aharonian, Y. Becherini, C. Boisson, A. Clapson, L. Costamante, L. Gérard, C. Medina, M. Naurois
and 6 more authors
M. Punch, F. Rieger, H. Sol, L. Stawarz, A. Zech, F. C. Collaboration
/ Abstract
We report the discovery of faint very high energy (VHE, E > 100 GeV) gamma-ray emission from the radio galaxy Centaurus A in deep observations performed with the H.E.S.S. experiment. A signal with a statistical significance of 5.0 sigma is detected from the region including the radio core and the inner kpc jets. The integral flux above an energy threshold of ~250 GeV is measured to be 0.8% of the flux of the Crab Nebula and the spectrum can be described by a power law with a photon index of 2.7 +/- 0.5_stat +/- 0.2_sys. No significant flux variability is detected in the data set. The discovery of VHE gamma-ray emission from Centaurus A reveals particle acceleration in the source to >TeV energies and, together with M 87, establishes radio galaxies as a class of VHE emitters.
Journal: arXiv: Cosmology and Nongalactic Astrophysics