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arXiv · 1505.01562

X-ray spectropolarimetric signature of a warped disk around a stellar-mass black hole

Yifan Cheng·Dan Liu·Sourabh Nampalliwar·Cosimo Bambi
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Abstract

Black holes in X-ray binaries are often assumed to be rotating perpendicular to the plane of the accretion disk and parallel to the orbital plane of the binary. While the Bardeen-Petterson effect forces the inner part of the accretion disk to be aligned with the equatorial plane of a spinning black hole, the disk may be warped such that the inclination angle of the outer part is different from that of the inner part. In this paper, we identify a possible observational signature of a warped accretion disk in the spectrum of the polarization degree of the continuum. Such a signature would provide direct evidence for the presence of a warped disk and, potentially, even a measure of the warp radius, which, in turn, could be used to infer the viscosity parameter of the disk.

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Yifan Cheng, Dan Liu, Sourabh Nampalliwar, Cosimo Bambi. 2015-05-07. X-ray spectropolarimetric signature of a warped disk around a stellar-mass black hole. https://doi.org/10.1088/0264-9381/33/12/125015

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