Book contents
- Frontmatter
- Contents
- Participants
- Preface
- Black holes, entropy, and information
- Gravitational waves from black-hole mergers
- Out-of-this-world physics: Black holes at future colliders
- Black holes in globular clusters
- Evolution of massive black holes
- Supermassive black holes in deep multiwavelength surveys
- Black-hole masses from reverberation mapping
- Black-hole masses from gas dynamics
- Evolution of supermassive black holes
- Black-hole masses of distant quasars
- The accretion history of supermassive black holes
- Strong field gravity and spin of black holes from broad iron lines
- Birth of massive black-hole binaries
- Dynamics around supermassive black holes
- Black-hole formation and growth: Simulations in general relativity
- Estimating the spins of stellar-mass black holes
- Stellar relaxation processes near the Galactic massive black hole
- Tidal disruptions of stars by supermassive black holes
- Where to look for radiatively inefficient accrection flows in low-luminosity AGN
- Making black holes visible: Accretion, radiation, and jets
Estimating the spins of stellar-mass black holes
Published online by Cambridge University Press: 11 April 2011
- Frontmatter
- Contents
- Participants
- Preface
- Black holes, entropy, and information
- Gravitational waves from black-hole mergers
- Out-of-this-world physics: Black holes at future colliders
- Black holes in globular clusters
- Evolution of massive black holes
- Supermassive black holes in deep multiwavelength surveys
- Black-hole masses from reverberation mapping
- Black-hole masses from gas dynamics
- Evolution of supermassive black holes
- Black-hole masses of distant quasars
- The accretion history of supermassive black holes
- Strong field gravity and spin of black holes from broad iron lines
- Birth of massive black-hole binaries
- Dynamics around supermassive black holes
- Black-hole formation and growth: Simulations in general relativity
- Estimating the spins of stellar-mass black holes
- Stellar relaxation processes near the Galactic massive black hole
- Tidal disruptions of stars by supermassive black holes
- Where to look for radiatively inefficient accrection flows in low-luminosity AGN
- Making black holes visible: Accretion, radiation, and jets
Summary
We describe a program that we have embarked on to estimate the spins of stellar-mass black holes in x-ray binaries. We fit the continuum x-ray spectrum of the radiation from the accretion disk using the standard thin disk model, and extract the dimensionless spin parameter a* = a/M of the black hole as a parameter of the fit. We have obtained results on three systems, 4U 1543–47 (a* = 0.7−0.85), GRO J1655−40 (0.65−0.8), and GRS 1915+105 (0.98−1), and have nearly completed the analysis of two additional systems. We anticipate expanding the sample of spin estimates to about a dozen over the next several years.
Introduction
The first black hole (BH), Cygnus X−1, was identified and its mass estimated in 1972. We now know of about 40 stellar-mass black holes in x-ray binaries in the Milky Way and neighboring galaxies. The masses of 21 of these, which range from ~5−15 M⊙, have been measured by observing the dynamics of their binary companion stars (Remillard & McClintock 2006; Orosz et al. 2007). In addition, it has become clear that virtually every galaxy has a supermassive black hole with M ~ 106−1010M⊙ in its nucleus. A few dozen of these supermassive BHs have reliable mass estimates, which have been obtained via dynamical observations of stars and gas in their vicinity (Begelman 2003).
With many mass measurements now in hand, the next logical step is to measure spin.
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- Black Holes , pp. 252 - 260Publisher: Cambridge University PressPrint publication year: 2011