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Structure of thermal pair clouds around gamma-ray-emitting black holesUsing 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.
Document ID
19910038060
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Liang, Edison P.
(Lawrence Livermore National Laboratory, Livermore; Stanford University CA, United States)
Date Acquired
August 15, 2013
Publication Date
February 1, 1991
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 367
ISSN: 0004-637X
Subject Category
Astrophysics
Accession Number
91A22683
Funding Number(s)
CONTRACT_GRANT: NGR-05-020-668
CONTRACT_GRANT: W-7405-ENG-48
Distribution Limits
Public
Copyright
Other

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