LIGO and Virgo have reported the detection of GW190521, from the merger of a binary black hole (BBH) with a total mass around 150 M ⊙ . While current stellar models limit the mass of any black hole (BH) remnant to about 40–50 M ⊙ , more massive BHs can be produced dynamically through repeated mergers in the core of a dense star cluster. The process is limited by the recoil kick (due to anisotropic emission of gravitational radiation) imparted to merger remnants, which can escape the parent cluster, thereby terminating growth. We study the role of the host cluster metallicity and escape speed in the buildup of massive BHs through repeated mergers. Almost independent of host metallicity, we find that a BBH of about 150 M ⊙ could be formed dynamically in any star cluster with escape speed ≳200 km s −1 , as found in galactic nuclear star clusters as well as the most massive globular clusters and super star clusters. Using ...

中文翻译：

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恒星团中黑洞合并的类似GW190521事件的起源

LIGO和处女座报告了通过合并质量约为150 M a的二元黑洞（BBH）来检测到GW190521。尽管目前的恒星模型将任何黑洞（BH）残留物的质量限制为大约40–50 M⊙，但可以通过在稠密星团的核心中反复合并动态地产生更大质量的BH。该过程受到合并残余物的反冲踢（由于重力辐射的各向异性发射）的限制，该残余物可以逃逸母体，从而终止生长。我们通过重复合并研究了主机簇金属性和逃逸速度在大规模BH积累中的作用。我们发现，几乎与主体金属无关，在逃逸速度为≳200km s -1的任何星团中都可以动态形成约150 M⊙的BBH，如在银河核恒星团，最大质量的球状星团和超级星团中发现的。使用...