论文标题
银河场中合并恒星的二进制黑洞合并
Binary black hole mergers from merged stars in the Galactic field
论文作者
论文摘要
大多数巨大的恒星都是在近距离的二进制物中发现的：（i）容易合并，（ii）伴随着另一个遥远的三级恒星（三元）。在这里，我们研究了由合并产品和三级伴侣组成的恒星后合并后二元。我们发现，合并后的二进制物起源于紧凑型恒星三元组，外部半轴轴$ a _ {\ rm out，init} \ sillessim10^1 \， - \， - \，10^2 \，\ rm au $提供了一种新的方式，可以使形成银色银色场中的binard Black bolggers合并。通过人口综合，我们估计它们对总黑洞合并率的贡献为$ \ MATHCAL {r}（z = 0）= 0.3 \， - \， - \，25.2 \，\ rm gpc^{ - 3} { - 3} \ \，yr^{ - 1} $。从恒星的合并后二进制组合形成的二元黑洞的质量比异常低。我们确定临界质量比$ q \ simeq0.5 $低于它们在该领域的总黑洞合并率的主导地位。我们表明，在包含其额外贡献之后，在银河场场景中二进制黑洞合并的质量比分布与重力波检测所推论的次数更好。
The majority of massive stars are found in close binaries which: (i) are prone to merge and (ii) are accompanied by another distant tertiary star (triples). Here, we study the evolution of the stellar post-merger binaries composed of the merger product and the tertiary companion. We find that post-merger binaries originating from compact stellar triples with outer semi-major axes $a_{\rm out,init}\lesssim10^1\,-\,10^2\,\rm AU$ provide a new way to form binary black hole mergers in the galactic field. By means of a population synthesis, we estimate their contribution to the total black hole merger rate to be $\mathcal{R}(z=0)=0.3\,-\,25.2\,\rm Gpc^{-3}\,yr^{-1}$. Merging binary black holes that form from stellar post-merger binaries have exceptionally low mass ratios. We identify a critical mass ratio $q\simeq0.5$ below which they dominate the total black hole merger rate in the field. We show that after including their additional contribution, the mass ratio distribution of binary black hole mergers in the galactic field scenario is in better agreement with that inferred from gravitational wave detections.
