Comptonization effects in spherical accretion onto black holes

Journal Article · Fri Apr 01 04:00:00 EST 1983 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/160876· OSTI ID:5832483

Ipser, J R; Price, R H

For spherical accretion of gas onto a black hole, dissipative heating (from magnetic reconnection), dissipation of turbulence, etc.) leads at high accretion rates to densities and temperatures at which Comptonization unavoidably plays an important role, both in determining gas temperature and in forming the emergent spectrum. A careful and reliable treatment of the interaction of the gas with the radiation field is greatly complicated by the necessity of dealing with the essentially nonlocal nature of Comptonization. We limit ourselves here to finding approximate descriptions of some observational features of such astrophysical objects with a simple, yet justifiable, Ansatz that evades the complexities of nonlocality. The results for accretion spectra are of interest, e.g., in connection with galactic halo objects (1--10/sup 5/ M/sub sun/). High mass (10/sup 7/--10/sup 10/ M/sub sun/) cases are of interest as models for active galactic nuclei. In particular, a very natural connection between the ratio of luminosity to Eddington luminosity and the hardness of X-ray spectra emerges, suggesting that the observed X-ray hardness ratios of luminous sources are a consequence of those sources being more or less Eddington limited.

• Research Organization: Department of Physics, University of Florida
• OSTI ID: 5832483
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 267:1; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BASIC INTERACTIONS
BLACK HOLES
COMPTON EFFECT
COOLING
COSMIC GASES
DISSIPATION FACTOR
ELASTIC SCATTERING
ELECTROMAGNETIC INTERACTIONS
ENERGY SPECTRA
FLUIDS
GALAXY NUCLEI
GASES
INTERACTIONS
MATHEMATICAL MODELS
RADIATIVE COOLING
SCATTERING
SPECTRA
STAR ACCRETION
STAR EVOLUTION
STAR MODELS