Accretion disk coronae

Journal Article · Tue Jun 01 04:00:00 EDT 1982 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/159991· OSTI ID:6807014

White, N E; Holt, S S

Recent observations of partial X-ray eclipses from 4U 1822-37 have shown that the central X-ray source in this system is diffused by a large Compton-thick accretion disk corona (ADC). We show that another binary, 4U-2129+47, also displays a partial eclipse and contains an ADC. The possible origin of an ADC is discussed and simple hydrostatic evaporated ADC model is developed which, when applied to 4U 1822-37, 4U 2129+47, and Cyg X-3, can explain their temporal and spectral properties. The quasi-sinusoidal modulation of three sources can be reconciled with the partial occulation of the ADC by a bulge at the edge of the accretion disk which is caused by the inflowing material. The height of this bulge is an order of magnitude larger than the standard thin disk height and is the result of turbulence in the outer region of the disk. The spectral properties of 4U 1822-37 and Cyg X-3 are very similar, while 4U 2129+47 exhibits a dissimilar spectrum which appears characteristic of Sco X-1/galactic bulge sources; the spectra of all three sources can be reconciled with Compton scattering of the original source spectrum by the ADC. Spectral variations with the overall intensity state of Cyg X-3 are probably caused by changes in the optical in a semidetached binary system which is close to its Eddington limit is likely to contain an optically thick ADC.

• Research Organization: Laboratory for High Energy Astrophysics, NASA/Goddard Space Flight Center
• OSTI ID: 6807014
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 257:1; ISSN ASJOA
• Country of Publication: United States
• Language: English

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640102 -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
640103* -- Astrophysics & Cosmology-- Quasi-Stellar
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71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BINARY STARS
COSMIC RAY SOURCES
COSMIC X-RAY SOURCES
ECLIPSE
STAR ACCRETION
STAR EVOLUTION
STARS
TURBULENCE
VARIATIONS