论文标题
旧黑洞上的新旋转：Exo 1846-031的Nustar光谱
A New Spin on an Old Black Hole: NuSTAR Spectroscopy of EXO 1846-031
论文作者
论文摘要
在静止至少25年之后，Black Hole候选EXO 1846-031在2019年爆发了。我们在2019年8月3日使用\ textit {nustar}观察了系统。3--79keV频谱显示出强大的相对反射特征。我们的基线模型给出了几乎最大的黑洞旋转值$ a = 0.997 _ { - 0.002}^{+0.001} $（$1σ$统计错误）。这个高价值名义上排除了带有中子恒星的中央发动机的可能性。使用多种模型，我们测试了测量的鲁棒性，以对积聚磁盘的密度，电晕的性质，磁盘连续模型的选择以及从积聚磁盘外部区域增加反射的假设。所有经过测试的模型都符合非常高的黑洞旋转值和高值，即倾斜$θ\ oft of73^\ circ $的内部积聚磁盘。我们讨论了这种自旋测量的含义，这些旋转测量对恒星质量黑洞的种群，包括已知的旋转，包括Ligo事件。
The black hole candidate EXO 1846-031 underwent an outburst in 2019, after at least 25 years in quiescence. We observed the system using \textit{NuSTAR} on August 3rd, 2019. The 3--79 keV spectrum shows strong relativistic reflection features. Our baseline model gives a nearly maximal black hole spin value of $a=0.997_{-0.002}^{+0.001}$ ($1σ$ statistical errors). This high value nominally excludes the possibility of the central engine harboring a neutron star. Using several models, we test the robustness of our measurement to assumptions about the density of the accretion disk, the nature of the corona, the choice of disk continuum model, and addition of reflection from the outer regions of the accretion disk. All tested models agree on a very high black hole spin value and a high value for the inclination of the inner accretion disk of $θ\approx73^\circ$. We discuss the implications of this spin measurement in the population of stellar mass black holes with known spins, including LIGO events.
