1. Estimating the Black Hole Spin for the X-Ray Binary MAXI J1820+070.
- Author
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Zhao, Xueshan, Gou, Lijun, Dong, Yanting, Tuo, Youli, Liao, Zhenxuan, Li, Yufeng, Jia, Nan, Feng, Ye, and Steiner, James F.
- Subjects
BLACK holes ,X-ray binaries ,BINARY black holes - Abstract
MAXI J1820+070 is a newly discovered black hole X-ray binary, whose dynamical parameters, namely the black hole mass, the inclination angle, and the source distance, have recently been estimated. Insight-HXMT have observed its entire outburst from 2018 March 14. In this work, we attempted to estimate the spin parameter a
* , using the continuum-fitting method and applying a fully relativistic thin disk model to the soft-state spectra obtained by Insight-HXMT. It is well known that a* is strongly dependent on three dynamical parameters in this method, and we have examined two sets of parameters. Adopting our preferred parameters: M = , i = 63° ± 3°, and D = 2.96 ± 0.33 kpc, we found a slowly spinning black hole of a* = 0.14 ± 0.09 (1σ), which gives a prograde spin parameter as the majority of other systems show. It is also possible for the black hole to have a retrograde spin (less than 0) if different dynamical parameters are taken. [ABSTRACT FROM AUTHOR]- Published
- 2021
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