Determining the spin of two stellar-mass black holes from disk reflection signatures
Autor: | Reis, R. C., Fabian, A. C., Ross, R. R., Miller, J. M. |
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Rok vydání: | 2009 |
Předmět: | |
Druh dokumentu: | Working Paper |
Popis: | We present measurements of the dimensionless spin parameters and inner-disk inclination of two stellar mass black holes. The spin parameter of SWIFT J1753.5-0127 and GRO J1655-40 are estimated by modelling the strong reflection signatures present in their XMM-Newton observations. Using a newly developed, self-consistent reflection model which includes the blackbody radiation of the disk as well as the effect of Comptonisation, blurred with a relativistic line function, we infer the spin parameter of SWIFT J1753.5-0127 to be 0.76 +0.11-0.15. The inclination of this system is estimated at 55+2-7 degrees. For GRO J1655-40 we find that the disk is significantly misaligned to the orbital plane, with an innermost inclination of 30+5-10 degrees. Allowing the inclination to be a free parameter we find a lower limit for the spin of 0.90, this value increases to that of a maximal rotating black hole when the inclination is set to that of the orbital plane of J1655-40. Our technique is independent of the black hole mass and distance, uncertainties in which are among the main contributors to the spin uncertainty in previous works. Comment: Accepted for publication in MNRAS, 9 pages, 11 figures |
Databáze: | arXiv |
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