Gamma rays from accreting matter onto collapsed objects

Abstract

In the spherical accretion onto massive objects, the matter may be heated up to temperatures as high as 10¹² °K. In such a hot plasma, the thermal bremsstrahlung (e-e and e-p) and π° decay from inelastic collisions of protons are the main γ-ray sources. We determined the γ -ray production spectra from the π° decay and from bremsstrahlung for different temperatures. The expected γ-ray spectra were evaluated too in order to fit experimental data. We have fitted COS B data from 3C 273 using a two temperatures plasma model. The best fit is for M˙²/M₈ = 3.2 10³(M_⊚/yr)² (M₈ is the black hole mass in 10⁸ M_⊚) which gives M˙ = 280 M_⊚/yr. The hard X-ray measurements do not contradict the bremsstrahlung spectrum.