Hostname: page-component-586b7cd67f-dsjbd Total loading time: 0 Render date: 2024-11-26T18:39:07.870Z Has data issue: false hasContentIssue false

High Energy Continuum Spectra from X-Ray Binaries

Published online by Cambridge University Press:  12 April 2016

S.N. Zhang*
Affiliation:
USRA/Marshall Space Flight Center, ES–84, Huntsville, AL 35812

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

A variety of high energy (>1 keV) spectra have been observed in recent years from Black Hole (BH) and Neutron Star (NS) X-ray Binaries (XB). Some common physical components exist between BHXBs and NSXBs, resulting in some high energy spectral features. A common component between a BHXB and a weakly magnetized NSXB is the inner accretion disk region extending very close to the surface (for a NS) or the horizon (for a BH). The inner disk radiation can be described by a multi-color blackbody (MCB) spectral model. The surface radiation of the NS can be approximated by a Single Color Blackbody (SCB) spectrum. For a strongly magnetized NSXB, the high energy emission is from its magnetosphere, characterised by a thermal bremsstrahlung (TB) spectrum. In both BHXBs and weakly magnetized NSXBs, a hot electron cloud may exist, producing the hard X-ray power law (photon index −1.5 to −2.0) with thermal cutoff (50–200 keV). It has been recently proposed that a converging flow may be formed near the horizon of a BH, producing a softer power law (photon index about −2.5) without cutoff up to several hundred keV. Based on these concepts we also discuss possible ways to distinguish between BH and NS XBs. Finally we discuss briefly spectral state transitions in both BH and NS XBs.

Type
Part 2. Black Hole Transient Sources
Copyright
Copyright © Astronomical Society of the Pacific 1997

References

Barret, D. et al. 1991, ApJ 379, 21 CrossRefGoogle Scholar
Barret, D., McClintock, J.E., Grindlay, J.E., 1996, ApJ 372, in pressGoogle Scholar
Bouchacourt, P. et al. 1984, ApJL 285, 6770 Google Scholar
Chakrabarti, S.K. & Titarchuk, L.G. 1995, ApJ, 455, 623 Google Scholar
Ebisawa, K., Titarchuk, L. & Chakrabarti, S.K., 1996, PASJ, 48, 1 Google Scholar
Ebisawa, K. et al. 1994, PASJ 46, 375 Google Scholar
Haardt, F., & Marashi, L. 1993, ApJ 413, 507 Google Scholar
Mitsuda, K. et al. 1984, PASJ 36, 741 Google Scholar
Mitsuda, K. et al. 1989, PASJ 41, p. 97 Google Scholar
Narayan, R. 1996, ApJ 462(1), 13641 Google Scholar
Shakura, N.I. & Sunyaev, R.A. 1973, A&A, 24, 337 Google Scholar
Shapiro, S.L. & Lightman, A.P. 1976 ApJ 204, 555 Google Scholar
Sunyaev, R.A., & Titarchuk, L., 1980, A&A 86, p. 121 Google Scholar
Tanaka, Y., & Lewin, W.H.G. 1995, in “X-ray Binaries”, eds. Lewin, W.H.G., van Paradijs, J., & van den Heuvel, E.P.J. Google Scholar
Titarchuk, L. 1996, Integral Workshop, St. Malo, France Google Scholar
van der Klis, M. & van Paradijs, J. 1994, A&A 281(1), L1720 Google Scholar
van der Klis, M. 1994, ApJS 92, 511519 Google Scholar
Vargas, M. et al. 1996, ApJ in pressGoogle Scholar
White, N.E. 1993, AIP Conf. Proc. 308, 5360 Google Scholar
White, N.E., Swank, J.H., Holt, S.S. 1983, ApJ 270, 711 Google Scholar
Zhang, S.N. et al. 1996a, A&AS in pressGoogle Scholar
Zhang, S.N. et al. 1996b, ApJ in pressGoogle Scholar
Zhang, S.N. et al. 1997a, ApJ submittedGoogle Scholar
Zhang, S.N. et al. 1997b, ApJ in pressGoogle Scholar
Zhang, S.N. et al. 1997c, ApJ submittedGoogle Scholar