Radiation Feedback in Hot Accretion-Disk Corona Models and
Application to GX 339-4
Boettcher, M., Liang, E. P., and Smith, I. A.
We present a detailed study of the observable effects of photoionization
and Comptonization of line and continuum radiation from a cold accretion
disk with a thin, warm, photoionized transition layer in the framework of
self-consistent accretion-disk corona models for Galactic black-hole
candidates. We use an iterative method to treat the non-linear radiation
feedback between the transition layer and the hot corona numerically using
a Monte-Carlo Comptonization code in combination with the photoionization
and line transfer code XSTAR. The subset of the parameter space allowed in
self-consistent accretion-disk corona systems on energetic grounds is
explored, checking for the emergence of emission lines and/or absorption
edges, with special emphasis on the spectral range below a few keV where
such features might become observable with the advent of the AXAF satellite,
and investigating the significance of the Compton reflection hump.
Comparing our model calculations to the broadband spectrum of GX 339-4, we
find good agreement with the observed spectral features, in particular the
absence of a Compton reflection component. We discuss how the future
detection of the predicted features at lower energies can be used to
constrain parameters.
Status:
1998, A&A, 339, 87.
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