On the Origin of the MeV Gamma-Ray Background

Abstract

In this paper, we suggest a new hypothesis for explaining the spectrum of the extragalactic MeV gamma-ray background as observed by COMPTEL and SMM. We propose that both the flux level and spectrum can be accounted for as a superposition of non-thermal MeV tails in the spectra of Seyfert galaxies and other AGN. Although present detectors are not sensitive enough to obtain MeV data from individual extragalactic sources, indirect evidence in support of our hypothesis is found in OSSE and COMPTEL observations of the galactic black hole candidate Cygnus X-1.