Black Hole Spin via Continuum Fitting and the Role of Spin in Powering Transient Jets. (arXiv:1303.1583v1 [astro-ph.HE])

Black Hole Spin via Continuum Fitting and the Role of Spin in Powering Transient Jets. (arXiv:1303.1583v1 [astro-ph.HE]):
The spins of ten stellar black holes have been measured using the
continuum-fitting method. These black holes are located in two distinct classes
of X-ray binary systems, one that is persistently X-ray bright and another that
is transient. Both the persistent and transient black holes remain for long
periods in a state where their spectra are dominated by a thermal accretion
disk component. The spin of a black hole of known mass and distance can be
measured by fitting this thermal continuum spectrum to the thin-disk model of
Novikov and Thorne; the key fit parameter is the radius of the inner edge of
the black hole's accretion disk. Strong observational and theoretical evidence
links the inner-disk radius to the radius of the innermost stable circular
orbit, which is trivially related to the dimensionless spin parameter a* (|a*|
\le 1). The ten spins that have so far been measured by this continuum-fitting
method range widely from a* \approx 0 to a* > 0.95. The robustness of the
method is demonstrated by the dozens or hundreds of independent and consistent
measurements of spin that have been obtained for several black holes, and
through careful consideration of many sources of systematic error. Among the
results discussed is a sharp dichotomy between the transient and persistent
black holes; the latter have higher spins and larger masses. Also discussed is
recently discovered evidence in the transient sources for a correlation between
the power of ballistic jets and black hole spin.