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Published April 1, 2019 | Submitted + Published
Journal Article Open

Constraints on the Spacetime Metric around Seven "Bare" AGNs Using X-Ray Reflection Spectroscopy


We present the study of a sample of seven "bare" active galactic nuclei observed with Suzaku. We interpret the spectrum of these sources with a relativistic reflection component and we employ our model relxill_nk to test the Kerr nature of their supermassive black holes. We constrain the Johannsen deformation parameters α_(13) and α_(22), in which the Kerr metric is recovered when α_(13) = α_(22) = 0. All our measurements are consistent with the hypothesis that the spacetime geometry around these supermassive objects is described by the Kerr solution. For some sources, we obtain quite strong constraints on α_(13) and α_(22) when compared to those found in our previous studies. We discuss the systematic uncertainties in our tests and the implications of our results.

Additional Information

© 2019. The American Astronomical Society. Received 2019 January 12; revised 2019 February 15; accepted 2019 February 23; published 2019 April 1. This work was supported by the National Natural Science Foundation of China (NSFC), grant No. U1531117, and Fudan University, grant No. IDH1512060. A.T. also acknowledges support from the China Scholarship Council (CSC), grant No. 2016GXZR89. A.B.A. also acknowledges the support from the Shanghai Government Scholarship (SGS). J.A.G. acknowledges support from the Alexander von Humboldt Foundation. J.J. is supported by the Cambridge Trust and the Chinese Scholarship Council Joint Scholarship Programme (201604100032). S.N. acknowledges support from the Excellence Initiative at Eberhard-Karls Universität Tübingen.

Attached Files

Published - Tripathi_2019_ApJ_874_135.pdf

Submitted - 1901.03064.pdf


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