=========================================================================
"Modelling the core emission of Centaurus A: effects of the second SSC photon generation"
Dr. Maria Petropoulou
Univ. of Athens

When:  Wednesday, 20 November 2013 at 14:30
Where: 2nd Floor Seminar Room

Abstract:
The recent discovery of high-energy (GeV) and very-high energy (TeV) gamma-ray emission from both the core and the extended lobes of Centaurus A, the nearest radio galaxy, has placed the source to the center of attention. So far, the leading interpreting scenario for its multiwavelength emission, at least below the TeV energy band, is the one-zone synchrotron self-Compton (SSC) emission model. Although this can, in principal, be applied on both blazar and radio galaxies, the conditions in the emitting region of the latter, e.g. low Doppler factor values, favors the emergence of the second SSC photon generation. Here we concentrate on the core emission of Centaurus A and we show that the second SSC component should not be neglected. It peaks in the sub-GeV energy range, but since most of the scatterings occur in the Klein-Nishina regime, it cannot account for the overall emission observed by Fermi. Finally, we discuss an alternative explanation of the GeV and TeV emission that involves a relativistic proton distribution.

=========================================================================