skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Structure of thermal pair clouds around gamma-ray-emitting black holes

Abstract

Using certain simplifying assumptions, the general structure of a quasi-spherical thermal pair-balanced cloud surrounding an accreting black hole is derived from first principles. Pair-dominated hot solutions exist only for a restricted range of the viscosity parameter. These results are applied as examples to the 1979 HEAO 3 gamma-ray data of Cygnus X-1 and the Galactic center. Values are obtained for the viscosity parameter lying in the range of about 0.1-0.01. Since the lack of synchrotron soft photons requires the magnetic field to be typically less than 1 percent of the equipartition value, a magnetic field cannot be the main contributor to the viscous stress of the inner accretion flow, at least during the high gamma-ray states. 34 refs.

Authors:
 [1]
  1. Lawrence Livermore National Laboratory, CA (USA) Stanford Univ., CA (USA)
Publication Date:
OSTI Identifier:
5976633
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal; (USA)
Additional Journal Information:
Journal Volume: 367; Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; BINARY STARS; GAMMA RADIATION; GALAXY NUCLEI; MILKY WAY; ACCRETION DISKS; BLACK HOLES; COSMIC GAMMA BURSTS; COSMIC X-RAY SOURCES; EMISSION SPECTRA; SPECTROSCOPY; STAR ACCRETION; VISCOSITY; COSMIC RADIATION; COSMIC RAY SOURCES; ELECTROMAGNETIC RADIATION; GALAXIES; IONIZING RADIATIONS; PRIMARY COSMIC RADIATION; RADIATIONS; SPECTRA; STAR EVOLUTION; STARS; 640102* - Astrophysics & Cosmology- Stars & Quasi-Stellar, Radio & X-Ray Sources; 640105 - Astrophysics & Cosmology- Galaxies

Citation Formats

Liang, E P. Structure of thermal pair clouds around gamma-ray-emitting black holes. United States: N. p., 1991. Web. doi:10.1086/169643.
Liang, E P. Structure of thermal pair clouds around gamma-ray-emitting black holes. United States. https://doi.org/10.1086/169643
Liang, E P. 1991. "Structure of thermal pair clouds around gamma-ray-emitting black holes". United States. https://doi.org/10.1086/169643.
@article{osti_5976633,
title = {Structure of thermal pair clouds around gamma-ray-emitting black holes},
author = {Liang, E P},
abstractNote = {Using certain simplifying assumptions, the general structure of a quasi-spherical thermal pair-balanced cloud surrounding an accreting black hole is derived from first principles. Pair-dominated hot solutions exist only for a restricted range of the viscosity parameter. These results are applied as examples to the 1979 HEAO 3 gamma-ray data of Cygnus X-1 and the Galactic center. Values are obtained for the viscosity parameter lying in the range of about 0.1-0.01. Since the lack of synchrotron soft photons requires the magnetic field to be typically less than 1 percent of the equipartition value, a magnetic field cannot be the main contributor to the viscous stress of the inner accretion flow, at least during the high gamma-ray states. 34 refs.},
doi = {10.1086/169643},
url = {https://www.osti.gov/biblio/5976633}, journal = {Astrophysical Journal; (USA)},
issn = {0004-637X},
number = ,
volume = 367,
place = {United States},
year = {Fri Feb 01 00:00:00 EST 1991},
month = {Fri Feb 01 00:00:00 EST 1991}
}