A Caltech Library Service

A Study of the Strong Gravity Region of the Black Hole in GS 1354–645

Xu, Yerong and Nampalliwar, Sourabh and Abdikamalov, Askar B. and Ayzenberg, Dimitry and Bambi, Cosimo and Dauser, Thomas and García, Javier A. and Jiang, Jiachen (2018) A Study of the Strong Gravity Region of the Black Hole in GS 1354–645. Astrophysical Journal, 865 (2). Art. No. 134. ISSN 0004-637X. doi:10.3847/1538-4357/aadb9d.

[img] PDF - Published Version
See Usage Policy.

[img] PDF - Submitted Version
See Usage Policy.


Use this Persistent URL to link to this item:


It is thought that the spacetime metric around astrophysical black holes is well described by the Kerr solution of Einstein's gravity. However, robust observational evidence of the Kerr nature of these objects is still lacking. Here we fit the X-ray spectrum of the stellar-mass black hole in GS 1354–645 with a disk reflection model beyond Einstein's gravity in order test the Kerr black hole hypothesis. We consider the Johannsen metric with the deformation parameters α_(13) and α_(22). The Kerr metric is recovered for α_(13) = α_(22) = 0. For α_(22) = 0, our measurements of the black hole spin and of the deformation parameter α 13 are a_* > 0.975 and −0.34 < α_(13) < 0.16, respectively. For α 13 = 0, we find a_* > 0.975 and −0.09 < α_(22) < 0.42. All the reported uncertainties are at 99% of confidence level for two relevant parameters.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Bambi, Cosimo0000-0002-3180-9502
Dauser, Thomas0000-0003-4583-9048
García, Javier A.0000-0003-3828-2448
Jiang, Jiachen0000-0002-9639-4352
Additional Information:© 2018. The American Astronomical Society. Received 2018 July 27; revised 2018 August 14; accepted 2018 August 18; published 2018 October 1. This work was supported by the National Natural Science Foundation of China (NSFC), grant No. U1531117, and Fudan University, grant No. IDH1512060. S.N. acknowledges support from the Excellence Initiative at Eberhard-Karls Universität Tübingen. A.B.A. also acknowledges the support from the Shanghai Government Scholarship (SGS). C.B. and J.A.G. also acknowledge support from the Alexander von Humboldt Foundation. J.J. is supported by the Cambridge Trust and the Chinese Scholarship Council Joint Scholarship Program (201604100032).
Group:Space Radiation Laboratory
Funding AgencyGrant Number
National Natural Science Foundation of ChinaU1531117
Fudan UniversityIDH1512060
Eberhard-Karls Universität TübingenUNSPECIFIED
Shanghai Government ScholarshipUNSPECIFIED
Alexander von Humboldt FoundationUNSPECIFIED
Cambridge Overseas TrustUNSPECIFIED
Chinese Scholarship Council201604100032
Subject Keywords:accretion, accretion disks; black hole physics; gravitation
Issue or Number:2
Record Number:CaltechAUTHORS:20181001-131357805
Persistent URL:
Official Citation:Yerong Xu et al 2018 ApJ 865 134
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:90071
Deposited By: George Porter
Deposited On:02 Oct 2018 19:42
Last Modified:16 Nov 2021 00:40

Repository Staff Only: item control page