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arXiv · 0906.4713

On the Prospect of Constraining Black-Hole Spin Through X-ray Spectroscopy of Hotspots

K. D. Murphy·T. Yaqoob·M. Dovčiak·V. Karas
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Abstract

Future X-ray instrumentation is expected to allow us to significantly improve the constraints derivedfrom the Fe K lines in AGN, such as the black-hole angular momentum (spin) and the inclination angle of the putative accretion disk. We consider the possibility that measurements of the persistent, time-averaged Fe K line emission from the disk could be supplemented by the observation of a localized flare, or "hotspot", orbiting close to the black hole. Although observationally challenging, such measurements would recover some of the information loss that is inherent to the radially-integrated line profiles. We present calculations for this scenario to assess the extent to which, in principle, black-hole spin may be measured. We quantify the feasibility of this approach using realistic assumptions about likely measurement uncertainties.

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K. D. Murphy, T. Yaqoob, M. Dovčiak, V. Karas. 2009-06-25. On the Prospect of Constraining Black-Hole Spin Through X-ray Spectroscopy of Hotspots. https://doi.org/10.1088/0004-637x%2F701%2F1%2F635

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