Testing General Relativity with the Reflection Spectrum of the Supermassive Black Hole in 1H0707-495

Phys Rev Lett. 2018 Feb 2;120(5):051101. doi: 10.1103/PhysRevLett.120.051101.


Recently, we have extended the x-ray reflection model relxill to test the spacetime metric in the strong gravitational field of astrophysical black holes. In the present Letter, we employ this extended model to analyze XMM-Newton, NuSTAR, and Swift data of the supermassive black hole in 1H0707-495 and test deviations from a Kerr metric parametrized by the Johannsen deformation parameter α_{13}. Our results are consistent with the hypothesis that the spacetime metric around the black hole in 1H0707-495 is described by the Kerr solution.