Massive black hole assembly in nuclear star clusters
Massive black hole assembly in nuclear star clusters
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DOI：
10.1103/physrevd.108.083012
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发表时间：
2022-12
影响因子：
5
通讯作者：
K. Kritos;E. Berti;J. Silk
中科院分区：
文献类型：
--
作者：
K. Kritos;E. Berti;J. Silk
核星星团在原星系的中心分裂成贫金属恒星，为质量为10^3 - 10^6 M_\odot $的中等质量黑洞的形成提供了理想的环境。我们利用Rapster，一个公共的快速集群进化代码中实现的半分析模型。我们实现简单的食谱恒星碰撞和气体吸积/驱逐到代码中，并确定制度，每个通道有助于通过重复合并恒星黑洞种子的动态形成的中等质量黑洞。我们发现，如果核团的初始平均密度$>10^8M_\odot\，{\rmpc}^{-3}$，那么中等质量黑洞在富气体环境中的形成几乎是不可避免的。在最重（$>10^7M_\odot$）和最紧凑（$<0.5~{\rm pc}$）的核团中，在1亿年内可以形成100万太阳质量的黑洞。我们证明，到今天为止，这些类似于矮星系中观察到的核簇范围，并且存在大质量黑洞形成过程的潜在引力波特征。
Nuclear star clusters, which fragment into metal-poor stars in situ at the centers of protogalaxies, provide ideal environments for the formation of intermediate-mass black holes with masses $10^3-10^6M_\odot$. We utilize the semianalytic model implemented in Rapster, a public rapid cluster evolution code. We implement simple recipes for stellar collisions and gas accretion/expulsion into the code and identify the regimes where each channel contributes to the dynamical formation of intermediate-mass black holes via repeated mergers of stellar black hole seeds. We find that intermediate-mass black hole formation in gas-rich environments is almost inevitable if the initial mean density of the nuclear cluster is $>10^8M_\odot\,{\rm pc}^{-3}$. A million solar mass black hole can form within 100~Myr in the heaviest ($>10^7M_\odot$) and most compact ($<0.5~{\rm pc}$) nuclear clusters. We demonstrate that by today these resemble the observed range of nuclear clusters in dwarf galaxies and that there are potential gravitational-wave signatures of the massive black hole formation process.