2008ApJ...679L..37L -
Astrophys. J., 679, L37-L40 (2008/May-3)
Precise measurement of the spin parameter of the stellar-mass black hole M33 X-7.
LIU J., McCLINTOCK J.E., NARAYAN R., DAVIS S.W. and OROSZ J.A.
Abstract (from CDS):
In prior work, Chandra and Gemini-North observations of the eclipsing X-ray binary M33 X-7 have yielded measurements of the mass of its black hole primary and the system's orbital inclination angle of unprecedented accuracy. Likewise, the distance to the binary is known to a few percent. In an analysis based on these precise results, 15 Chandra and XMM-Newton X-ray spectra, and our fully relativistic accretion disk model, we find that the dimensionless spin parameter of the black hole primary is a*=0.77±0.05. The quoted 1 σ error includes all sources of observational uncertainty. Four Chandra spectra of the highest quality, which were obtained over a span of several years, all lead to the same estimate of spin to within statistical errors (2%), and this estimate is confirmed by 11 spectra of lower quality. There are two remaining uncertainties: (1) the validity of the relativistic model used to analyze the observations, which is being addressed in ongoing theoretical work; and (2) our assumption that the black hole spin is approximately aligned with the angular momentum vector of the binary, which can be addressed by a future X-ray polarimetry mission.
Abstract Copyright:
∼
Journal keyword(s):
Stars: Binaries: General - Black Hole Physics - Galaxies: Individual: Messier Number: M33 - X-Rays: Binaries
Errata:
erratum vol. 719, p. L109 (2010)
CDS comments:
M33 X-7 = [LDC81] 7
Simbad objects:
7
Full paper
View the references in ADS
To bookmark this query, right click on this link: simbad:2008ApJ...679L..37L and select 'bookmark this link' or equivalent in the popup menu