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arXiv · 1904.08027

Testing the Kerr hypothesis using X-ray reflection spectroscopy with NuSTAR data of Cygnus X-1 in the soft state

Honghui Liu·Askar B. Abdikamalov·Dimitry Ayzenberg·Cosimo Bambi·Thomas Dauser·Javier A. Garcia·Sourabh Nampalliwar
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Abstract

We continue exploring the constraining capabilities of X-ray reflection spectroscopy to test the Kerr-nature of astrophysical black holes and we present the results of our analysis of two NuSTAR observations of Cygnus X-1 in the soft state. We find that the final measurement can strongly depend on the assumption of the intensity profile. We conclude that Cygnus X-1 is not suitable for tests of general relativity using X-ray reflection spectroscopy and we discuss the desired properties of a source to be a good candidate for our studies.

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Honghui Liu, Askar B. Abdikamalov, Dimitry Ayzenberg, Cosimo Bambi, Thomas Dauser, Javier A. Garcia, Sourabh Nampalliwar. 2019-04-17. Testing the Kerr hypothesis using X-ray reflection spectroscopy with NuSTAR data of Cygnus X-1 in the soft state. https://doi.org/10.1103/physrevd.99.123007

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