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C.R. Shrader (NASA/GSFC & USRA), L.G. Titarchuk (GMU, NRL, NASA/GSFC)
We describe our study of the effects outflowing plasma on the high-energy continuum spectra of accretion powered compact objects. The basic idea is that Thomson scattering of the photons from the central source entering the expanding flow experience a decrease of their energy which is of first order in v/c, where v is the outflow velocity and c is the speed of light. We predict that the emergent spectrum should be closely related to the distribution of photons diffusing through the wind. To test this hypothesis, we have developed an analytical formulation for the emergent spectrum of a compact accretion driven system in a circumstellar wind environment, and performed model fitting on several Galactic X-ray binaries. Notably, Cygnus X-3 is which is widely believed to be characterized by hot, dense circumstellar winds provides the prototypical test case. Observational data from INTEGRAL and RXTE are included in our analysis. In addition to Cyg X-3, we have applied our model to several other well known X-ray binaries, for which the presence of wind outflow is not firmly established, but may nonetheless be present. We further consider the possibility that the well documented distortion of the pure power-law continuum above 10 keV, the so called “reflection bump”, may in some cases be explained by the spectral softening effects of the outflow.
The author(s) of this abstract have provided an email address for comments about the abstract: Chris.R.Shrader@gsfc.nasa.gov
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Bulletin of the American Astronomical Society, 35#5
© 2003. The American Astronomical Soceity.