Positron annihilation radiation from the nuclei of Seyfert Galaxies

Journal Article · Sat Jan 01 04:00:00 EST 1983 · Adv. Space Res.; (United States)

DOI:https://doi.org/10.1016/0273-1177(83)90025-X· OSTI ID:6126280

Bassani, L; Dean, A J

Recent gamma-ray observations of two Seyfert Galaxies are interpreted in terms of electron-positron pair annihilation radiation. A simplified scenario is envisaged in which a massive black hole is accreting material from an optically thin disk characterized by a hot, more than 10 billion K e + or - plasma. At these very high temperatures, the 511 keV line emission loses its characteristic features to become both broadened and blueshifted. Observational X and gamma-ray data are used to investigate the possibility that the bump in the spectral emission at photon energies of about 1 MeV observed in Seyfert galaxies may be due to this annihilation feature. In particular, the self consistency of the parameters estimated from the gamma-ray data is explored. Furthermore, the possibility that this annihilation feature may be mirrored in the cosmic diffuse background is investigated and, under this assumption, the maximum temperature of the annihilation region and the average annihilation rate for Seyfert galaxies is calculated.

• Research Organization: Southampton Univ., England
• OSTI ID: 6126280
• Journal Information: Adv. Space Res.; (United States), Journal Name: Adv. Space Res.; (United States) Vol. 3; ISSN ASRSD
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BACKGROUND RADIATION
BLACK HOLES
ELECTROMAGNETIC RADIATION
ELECTRONS
ELEMENTARY PARTICLES
EMISSION SPECTRA
FERMIONS
GALAXIES
GALAXY NUCLEI
GAMMA RADIATION
IONIZING RADIATIONS
LEPTONS
RADIATIONS
SEYFERT GALAXIES
SPECTRA