1996/07/10 by A. Comastri, T. Di Girolamo, Comastri, A. +3
Physics and Astronomy · #Astrophysics (astro-ph) #FOS: Physical sciences #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9607050
4 pages, AA LaTeX, plus 3 .ps figures and style file l-aa.sty, uuencoded, gzip tar file, to appear in Astronomy and Astrophysics Supplement
arxiv created 1996/07/10 · arxiv updated 2009/12/01
The contribution of discrete sources to the gamma--ray background is modeled. Flat spectrum radio quasars are known to make a substantial contribution to the hard (E > 100 MeV) background. The so called ``MeV bump", however, cannot be accounted for in terms of known classes of sources even taking into account the newly discovered class of objects with a broad band spectrum sharply peaked in the MeV range (``MeV blazars"). Even in the most optimistic case the predicted intensity falls short of at least a factor three.