| タイトル | NuSTAR Observations of the Black Hole GS 1354-645: Evidence of Rapid Black Hole Spin |
| 著者（英） | Craig, W. W.; Stern, D. K.; Harrison, F. A.; Walton, D. J.; Zhang, W. W.; El-Batal, A. M.; Boggs, S. E.; Tomsick, J.; Christensen, F. E.; Fuerst, F.; Reynolds, M. T.; Miller, J. M.; Hailey, C. J. |
| 著者所属（英） | NASA Goddard Space Flight Center |
| 発行日 | 2016-07-19 |
| 言語 | eng |
| 内容記述 | We present the results of a NuSTAR study of the dynamically confirmed stellar-mass black hole GS 1354645. The source was observed during its 2015 "hard" state outburst; we concentrate on spectra from two relatively bright phases. In the higher-flux observation, the broadband NuSTAR spectra reveal a clear, strong disk reflection spectrum, blurred by a degree that requires a black hole spin of a = cJ/ GM(sup 2) > or = 0.98 (1(sigma) statistical limits only). The fits also require a high inclination: theta approx. = 75(2)deg. Strong "dips" are sometimes observed in the X-ray light curves of sources viewed at such an angle; these are absent, perhaps indicating that dips correspond to flared disk structures that only manifest at higher accretion rates. In the lower flux observation, there is evidence of radial truncation of the thin accretion disk. We discuss these results in the context of spin in stellar-mass black holes, and inner accretion flow geometries at moderate accretion rates. |
| NASA分類 | Astrophysics |
| レポートNO | GSFC-E-DAA-TN41102 |
| 権利 | Copyright |
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