Testing the Kerr black hole hypothesis using X-ray reflection spectroscopy and a thin disk model with finite thickness
X-ray reflection spectroscopy is a powerful tool for probing the strong gravity region of black holes and can be used for testing general relativity in the strong field regime. Simplifications of the available relativistic reflection models limit the capability of performing accurate measurements of the properties of black holes. In this paper, we present an extension of the model relxill_nk in which the accretion disk has a finite thickness rather than being infinitesimally thin. We employ the accretion disk geometry proposed by Taylor & Reynolds and we construct relativistic reflection models for different values of the mass accretion rate of the black hole. We apply the new model to high-quality Suzaku data of the X-ray binary GRS 1915+105 to explore the impact of the thickness of the disk on tests of the Kerr metric.
© 2020 The American Astronomical Society. Received 2020 April 2; revised 2020 July 12; accepted 2020 July 13; published 2020 August 14. This work was supported by the Innovation Program of the Shanghai Municipal Education Commission, Grant No. 2019-01-07-00-07-E00035, and the National Natural Science Foundation of China (NSFC), Grant No. 11973019. A.B.A. also acknowledges support from the Shanghai Government Scholarship (SGS). J.A.G. and S.N. acknowledge support from the Alexander von Humboldt Foundation. C.B., J.A.G., S.N., and A.T. are members of the International Team 458 at the International Space Science Institute (ISSI), Bern, Switzerland, and acknowledge support from ISSI during the meetings in Bern.
Submitted - 2003.09663.pdf
Published - Abdikamalov_2020_ApJ_899_80.pdf