Gamma-rays from the Funnels of Thick Accretion Disks around Active Galactic Nuclei

We analyse the propagation of particles in the narrow funnel of a thick accretion disk. It is assumed that: (1) the funnel walls emit black body radiation with temperature decreasing outwards; (2) the magnetic and electric elds are longitudinal in the funnel. Such a scenario is consistent with models in which a large potential drop is induced by a rotating massive black hole threaded by a magnetic eld (Blandford & Znajek 1977, Macdonald & Thorne 1982). The interaction of relativistic protons with thermal photons from the funnel results in direct production of e pairs and/or pions. We discuss the relative importance of these processes for diierent conditions in the funnel (temperature and electric eld pro-les). Injected e pairs interact with thermal photons in the Thomson or Klein-Nishina regime. Under some conditions, a pair avalanche results, which we assume saturates in the production of stable bunches, containing almost equal numbers of electrons and positrons. As a consequence, highly collimated-ray photons are produced. We obtain-ray spectra from our model in order to test its applicability to the-ray emitting AGNs recently reported by EGRET.