We construct a relativistic reflection model in a non-Kerr spacetime in which, depending on the value of the deformation parameter of the metric, there are black hole solutions with spin parameter ∣a∗∣>1. We apply our model to fit Suzaku data of four Seyfert galaxies (Ton S180, Ark 120, 1H0419-577, and Swift J0501.9-3239). These galaxies host at the center supermassive black holes that were previously interpreted as near-extremal Kerr black holes. For Ton S180 and 1H0419-577, our measurements are still consistent with the Kerr hypothesis. For Ark 120 and Swift J0501.9-3239, the Kerr solution is not recovered at 3-σ. We discuss our results and possible systematic uncertainties in the model.
@article{arxiv.1908.05177,
title = {Relativistic reflection spectra of super-spinning black holes},
author = {Biao Zhou and Ashutosh Tripathi and Askar B. Abdikamalov and Dimitry Ayzenberg and Cosimo Bambi and Sourabh Nampalliwar and Menglei Zhou},
journal= {arXiv preprint arXiv:1908.05177},
year = {2020}
}