MODEL FOR THE HIGH ENERGY EMISSION FROM CEN A

Abstract

Centaurus A (Cen A) is the closest active galaxy (3.8 Mpc) and presents strong activity over a wide spectral range from radio to very-high energy gamma-rays. We propose a lepto-hadronic model for the high-energy emission, assuming that particles can be shock-accelerated at the inner jets of this source. The primary electron and proton distributions are obtained in the acceleration zone, taking into account the relevant cooling processes such as synchrotron emission, inverse-Compton up-scattering of photons in both Thomson and Klein–Nishina regimes, proton–proton and proton–photon interactions. Considering the effects of internal absorption of gamma-rays, we compare our results with current observational data obtained by HESS and Fermi. We compute also the distribution of secondary pions and muons produced by hadronic interactions. The expected high-energy neutrino signal is calculated and the possibility of detection with KM3NET or similar arrays is discussed.