The origin of the extragalactic gamma-ray background in the 35-100 MeV range

Abstract

view Abstract Citations (6) References (27) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Origin of the Extragalactic gamma -Ray Background in the 35--100 MeV Range Young, E. C. M. ; Yu, K. N. Abstract The SAS 2 γ-ray data and the Lick Survey galaxy count data have been used to determine statistically the absolute luminosities of quasars in the 35-100 MeV range. A functional relationship between these luminosities and those at 2500 A of quasars is then established by using the "detections and bounds" (DB) method. Making use of the optical luminosity function given by Marshall in 1985 and the functional relationship we have obtained, and performing the cosmological integration, we find that the contribution of quasars to the diffuse γ-ray background is (2.06^+0.71^_-0.53_) x 10^-5^ photons cm^-2^ s^-1^ sr^-2^, which is about 40% of the total background. In the same way, by using the optical luminosity function reported by Cheng and colleagues in 1985, we obtain the contribution of Seyfert galaxies (class 1 and 1.5) to be (1.04^+1.45^_-0.61_) x 10^-5^ photons cm^-2^ s^-1^ sr^-1^, i.e., about 20% of the total. Therefore the extragalactic γ-ray background in the 35-100 MeV range is likely to be generated mainly by discrete extragalactic objects. Publication: The Astrophysical Journal Pub Date: July 1988 DOI: 10.1086/185192 Bibcode: 1988ApJ...330L...5Y Keywords: Background Radiation; Extraterrestrial Radiation; Gamma Ray Astronomy; Quasars; Seyfert Galaxies; X Ray Sources; Active Galactic Nuclei; Big Bang Cosmology; Red Shift; Stellar Luminosity; Astrophysics; GALAXIES: SEYFERT; GAMMA RAYS: GENERAL; QUASARS full text sources ADS | data products SIMBAD (4) NED (4)