Spectral analysis of new black hole candidate AT2019wey observed by NuSTAR
Feng Y, Zhao X, Gou L, Li Y, Steiner JF, Garcia JA, Wang Y, Jia N, Liao Z, Li H (2022)
Publication Type: Journal article
Publication year: 2022
Journal
Book Volume: 65
Journal Issue: 1
DOI: 10.1007/s11433-021-1790-7
Abstract
AT2019wey is a new galactic X-ray binary that was first discovered as an optical transient by the the Asteroid Terrestrial-impact Last Alert System (ATLAS) on December 7, 2019. AT2019wey consists of a black hole candidate as well as a low-mass companion star (M-star less than or similar to 1.0M(circle dot)) and is likely to have a short orbital period (P-orb less than or similar to 16 h). Although AT2019wey began activation in the X-ray band on March 8, 2020, it did not enter the soft state during almost the entire outburst. In this study, we present a detailed spectral analysis of AT2019wey in the low/hard state during its X-ray outburst on the basis of Nuclear Spectroscopic Telescope Array (NuSTAR) observations. We obtain tight constraints on several of its important physical parameters by applying the state of the art relxill relativistic reflection model family. In particular. we determine that the measured inner radius of the accretion disk is most likely to have extended to the innermost stable circular orbit (ISCO) radius. i.e.. R-in = 1.38(-0.1)(6)(+0.23) R-ISCO. Hence, assuming R-in=R-ISCO, we find the spin of AT2019wey to be a(*) similar to 0.97, which is close to the extreme and an inner disk inclination angle of i similar to 22 degrees. Additionally, according to our adopted models, AT2019wey tends to have a relatively high iron abundance of A(Fe) similar to 5A(Fe,circle dot) and a high disk ionization state of log xi similar to 3.4.
Involved external institutions
Chinese Academy of Sciences (CAS) / 中国科学院
China (CN)
Harvard University
United States (USA) (US)
California Institute of Technology (Caltech)
United States (USA) (US)
Jimei University
China (CN)
China (CN)
Harvard University
United States (USA) (US)
California Institute of Technology (Caltech)
United States (USA) (US)
Jimei University
China (CN)
How to cite
APA:
Feng, Y., Zhao, X., Gou, L., Li, Y., Steiner, J.F., Garcia, J.A.,... Li, H. (2022). Spectral analysis of new black hole candidate AT2019wey observed by NuSTAR. Science China-Physics Mechanics & Astronomy, 65(1). https://dx.doi.org/10.1007/s11433-021-1790-7
MLA:
Feng, Ye, et al. "Spectral analysis of new black hole candidate AT2019wey observed by NuSTAR." Science China-Physics Mechanics & Astronomy 65.1 (2022).
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