Gamma-ray emission from interactions between jets and BLR clouds

Abstract

Blazars -active galactic nuclei with a jet pointing towards the observer- are the most numerous γ-ray sources detected until date. In this work we show preliminary results of a model in which broad-line region (BLR) clouds penetrate in the jet, producing shocks capable of accelerating relativistic electrons; these electrons emit γ-rays when they interact with the photons coming from the BLR clouds. We calculate semi-analytically the dynamical evolution of a typical cloud inside the jet, the energy distribution of the locally accelerated electrons, and the high-energy emission the latter produce, taking into account relativistic effects. We estimate the dutycycle of these interactions in order to find whether they occur as discrete events or almost continuous. We compare the observed γ-ray fluxes with the ones predicted by our model and discuss the implications in terms of particle acceleration efficiency and mass-loading in the blazar jets.