Evaluation of the contribution of different types of galaxies to the cosmic diffuse background based on gamma-ray observations

Conference · Sun Jan 01 04:00:00 EST 1984 · Adv. Space Res.; (United States)

OSTI ID:6047362

Bassani, L; Dean, A J; Di Cocco, G

The relative contribution to the gamma-ray background of different types of sources, namely Seyfert galaxies, quasars, BL Lac objects, radio galaxies, and field galaxies is estimated under the hypothesis that the cosmic diffuse flux is the result of a superposition of many unresolved galaxies. The gamma-ray data indicate that the Seyfert volume emissivity matches that of the diffuse background at few hundred keV and exceeds it at higher energies by as much as a factor of about four. While normal galaxies contribute less than 0.1 percent, BL Lac objects, quasars and radio galaxies may contribute as much as 5-10 percent each, even without significant evolution. In this paper, different ways of reconciling the observational data on active galaxies with the measured diffuse background level are explored. 17 references.

• Research Organization: Southampton Univ., England
• OSTI ID: 6047362
• Report Number(s): CONF-8307144-
• Conference Information: Journal Name: Adv. Space Res.; (United States) Journal Volume: 3
• Country of Publication: United States
• Language: English

Related Subjects

640101* -- Astrophysics & Cosmology-- Cosmic Radiation
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ASTRONOMY
BACKGROUND RADIATION
BL LACERTAE OBJECTS
COSMIC RADIATION
COSMIC RADIO SOURCES
ELECTROMAGNETIC RADIATION
GALAXIES
GAMMA ASTRONOMY
IONIZING RADIATIONS
MICROWAVE RADIATION
ORIGIN
QUASARS
RADIATIONS
RADIO GALAXIES
RELICT RADIATION
SEYFERT GALAXIES