论文标题
第一个隔离恒星质量黑洞的二进制起源，该黑洞用天体微透镜检测到
A binary origin for the first isolated stellar-mass black hole detected with astrometric microlensing
论文作者
论文摘要
银河系被认为可以容纳数亿个静止的恒星质量黑洞（BHS）。在过去的十年中，其中一些物体可能通过重力微透明事件被发现。所有这些检测导致速度和镜头质量之间的变性。最近，随着OB110462的最新星体微透镜检测，这种退化率首次解除。但是，两项独立研究报告了此事件的镜头质量非常不同。 Sahu等。 （2022）推断出镜头质量为7.1 $ \ pm $ 1.3 MSUN，与BH一致，而Lam等人。 （2022）推断1.6-4.2 msun，与中子星或BH一致。在这里，我们研究了该领域形成的孤立BHS的景观。特别是，我们专注于四个子人群的质量和质量速度：单星级起源的孤立BHS，二进制二进制形式的破坏BHS，具有紧凑对象伴侣的主要序列恒星和双重紧凑的对象合并。我们的模型预测，大多数（$ \ gtrsim $ 70％）以银河系为单位的BHS都是二进制的。但是，非相互作用导致最大的BHS（$ \ gtrsim $ 15-20 msun）主要是单一起源。根据OB110462是一个自由浮动的紧凑型物体的假设，我们得出的结论是，它更有可能是最初属于二进制系统的BH。我们的结果表明，低质量BH微覆化事件对于以银河系的方式了解大型恒星的二元演化很有用，而高质量BH镜头对于探测单个恒星的演化很有用。
The Milky Way is believed to host hundreds of millions of quiescent stellar-mass black holes (BHs). In the last decade, some of these objects have been potentially uncovered via gravitational microlensing events. All these detections resulted in a degeneracy between the velocity and the mass of the lens. This degeneracy has been lifted, for the first time, with the recent astrometric microlensing detection of OB110462. However, two independent studies reported very different lens mass for this event. Sahu et al. (2022) inferred a lens mass of 7.1 $\pm$ 1.3 Msun, consistent with a BH, while Lam et al. (2022) inferred 1.6-4.2 Msun, consistent with either a neutron star or a BH. Here, we study the landscape of isolated BHs formed in the field. In particular, we focus on the mass and center-of-mass speed of four sub-populations: isolated BHs from single-star origin, disrupted BHs of binary-star origin, main-sequence stars with a compact object companion, and double compact object mergers. Our model predicts that most ($\gtrsim$ 70%) isolated BHs in the Milky Way are of binary origin. However, non-interactions lead to most massive BHs ($\gtrsim$ 15-20 Msun) being predominantly of single origin. Under the assumption that OB110462 is a free-floating compact object we conclude that it is more likely to be a BH originally belonging to a binary system. Our results suggest that low-mass BH microlensing events can be useful to understand binary evolution of massive stars in the Milky Way, while high-mass BH lenses can be useful to probe single stellar evolution.
