论文标题
动态双黑洞及其主机群集特性
Dynamical double black holes and their host cluster properties
论文作者
论文摘要
我们研究了恒星簇的全球性质及其双黑洞（DBH）种群之间的关系。我们使用代码{\ tt nbody6}来进化一套$ \ MATHCAL {O}（10^4）$ M $ _ \ odot $和变化的初始参数的星团群体模型套件。我们得出的结论是，簇金属性在确定簇的寿命方面起着最重要的作用，而最初的半质量半径在设定中央群集区域的BH交换相互作用速率方面占主导地位。我们发现，相互作用的BHS的质量，而不是与其他BH的相互作用发生的频率，在群集的热膨胀和最终蒸发中更为重要。我们制定了一种新颖的方法，可以轻松量化每个模型中BH-BH动力学活性的程度。我们报告了介绍的十个$ n $ body型号的不同类型（Inspiral，Eccentric，contrawical）的12 $ n $ body型模型。我们的DBH合并效率为3--4 $ \ times10^{ - 5} $合并每个m $ _ \ odot $。我们注意到，簇初始密度在确定DBH合并的数量中起着最关键的作用，并且潜在的过渡密度点（介于1.2-3.8 $ \ 3.8 $ \ times10^3 $ _ \ odot $/pc $^3 $）以下以下是群集中的密度和群集密度越来越高于群集bh的群集，而bh则在群集内的群集中增加了群集的数量。还讨论了集群中动力相互作用历史的重要性在设置弹出DBH合并的途径中的重要性。我们的发现与观察到的Ligo-Virgo DBH合并相匹配。
We investigate the relationship between the global properties of star clusters and their double black hole (DBH) populations. We use the code {\tt NBODY6} to evolve a suite of star cluster models with an initial mass of $\mathcal{O}(10^4)$M$_\odot$ and varying initial parameters. We conclude that cluster metallicity plays the most significant role in determining the lifespan of a cluster, while the initial half-mass radius is dominant in setting the rate of BH exchange interactions in the central cluster regions. We find that the mass of interacting BHs, rather than how frequently their interactions with other BHs occur, is more crucial in the thermal expansion and eventual evaporation of the cluster. We formulate a novel approach to easily quantify the degree of BH-BH dynamical activity in each model. We report 12 in-cluster and three out-of-cluster (after ejection from the cluster) DBH mergers, of different types (inspiral, eccentric, hierarchical) across the ten $N$-body models presented. Our DBH merger efficiency is 3--4$\times10^{-5}$ mergers per M$_\odot$. We note the cluster initial density plays the most crucial role in determining the number of DBH mergers, with the potential presence of a transitional density point (between 1.2-3.8$\times10^3$M$_\odot$/pc$^3$) below which the number of in-cluster mergers increases with cluster density and above which the increased stellar density acts to prevent in-cluster BH mergers. The importance of the history of dynamical interactions within the cluster in setting up the pathways to ejected DBH mergers is also discussed. Our findings show a broad match with observed LIGO-Virgo DBH mergers.
