Physical Parameter Estimation in Black Hole X-Ray Binaries
C.R. Shrader & L.G. Titarchuk
Abstract
We describe a recently developed method for extracting
physical information on black-hole X-ray binary
systems from their X- and gamma-ray spectral
properties. The high-energy continuum is interpreted as
thermal emission from an accretion disk and Comptonized
emission from a relativistic bulk inflow. From the
absolute normalization and an empirical determination of the
hardening factor - the ratio of color-to-effective
temperature - we can with minimal model dependency, use
observables to determine parameters of the system such
as the mass-to-distance ratio, and if
the distance can be independently determined, the mass
accretion rate, and the disk effective radius. Application
of this methodology to recent X- and gamma-
ray observations are presented, with emphasis on the
recently discovered X-ray nova XTE J1550-564.
This object has been observed with the Compton
Gamma Ray Observatory, including pointed observations with OSSE
at several epochs, and documentation of its high-
energy flux history by BATSE. These data are
combined with soft-X-ray data from the
Rossi X-Ray Timing Explorer for our analysis.
Information from dynamical studies of the quiescent binary
system (by other groups) is beginning to emerge,
and we will compare and our results with
any results available from those studies.
File translated from TEX by TTH, version 2.32.
On 16 Jul 1999, 09:18.