Testing general relativity with the reflection spectrum of the supermassive black hole in 1H0707$-$495

TL;DR

This study uses an extended X-ray reflection model to analyze observational data of a supermassive black hole, testing for deviations from the Kerr metric and supporting the Kerr solution's validity.

Contribution

We extended the relxill model to test black hole spacetime metrics and applied it to real data, providing new constraints on deviations from Kerr geometry.

Findings

Results are consistent with the Kerr metric hypothesis.

No significant deviations from Kerr metric detected.

Supports the validity of the Kerr solution in strong gravity regimes.

Abstract

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 $\alpha_{13}$. Our results are consistent with the hypothesis that the spacetime metric around the black hole in 1H0707-495 is described by the Kerr solution.