Binary black hole mergers from LIGO/Virgo O1 and O2: Population inference combining confident and marginal events
Binary black hole mergers from LIGO/Virgo O1 and O2: Population inference combining confident and marginal events
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DOI：
10.1103/physrevd.102.123022
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发表时间：
2020-08
影响因子：
5
通讯作者：
Javier Roulet;T. Venumadhav;B. Zackay;L. Dai;M. Zaldarriaga
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文献类型：
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作者：
Javier Roulet;T. Venumadhav;B. Zackay;L. Dai;M. Zaldarriaga
我们进行统计推断的天体物理人口的二元黑洞（BBH）合并期间观察到的先进LIGO和先进处女座的前两个观测运行，包括在GWTC-1和IAS目录中报告的事件。我们得到一个新的形式主义，充分和一贯的任意意义的事件。我们进行了一个软件注入活动，以获得一组模拟天体物理事件受到我们的选择效果，并使用搜索背景来计算候选事件的BBH人口的几个唯象模型的天体物理概率$p_{\rmastro}$。最后，我们结合联合收割机从个别事件的信息来推断合并的速率，自旋，质量，质量比和红移分布。现有的人口不区分随机自旋的有效自旋参数的传播，和一个小的，但非零的事件从潮汐扭矩恒星祖先的分数。质量分布与截止值为$m_{\rm max} = 41^{+10}_{-5}\，\rm M_\odot$的分布一致，而质量比有利于质量相等;平均质量比$\bar q> 0.67$。速率随红移没有明显的变化。结果表明，当初始质量在20 ~ 30 μ M之间，质量比q > 0.5，z = 0.2时，BBH的合并速率为1.5 ~ 5.3 μ m，Gpc^{-3} yr^{-1}$（90% c.l.）这些边界是模型无关的，并且比所有BBH合并的局部速率更紧，因此是对所有祖模型的鲁棒约束。包括在我们的目录中的事件增加了关于BBH人口的Fisher信息$\sim 47\%$，并收紧了对人口参数的约束。
We perform a statistical inference of the astrophysical population of binary black hole (BBH) mergers observed during the first two observing runs of Advanced LIGO and Advanced Virgo, including events reported in the GWTC-1 and IAS catalogs. We derive a novel formalism to fully and consistently account for events of arbitrary significance. We carry out a software injection campaign to obtain a set of mock astrophysical events subject to our selection effects, and use the search background to compute the astrophysical probabilities $p_{\rm astro}$ of candidate events for several phenomenological models of the BBH population. Finally, we combine the information from individual events to infer the rate, spin, mass, mass-ratio and redshift distributions of the mergers. The existing population does not discriminate between random spins with a spread in the effective spin parameter, and a small but nonzero fraction of events from tidally-torqued stellar progenitors. The mass distribution is consistent with one having a cutoff at $m_{\rm max} = 41^{+10}_{-5}\,\rm M_\odot$, while the mass ratio favors equal masses; the mean mass ratio $\bar q> 0.67$. The rate shows no significant evolution with redshift. We show that the merger rate restricted to BBHs with a primary mass between 20 and $30\, \rm M_\odot$, and a mass ratio $q > 0.5$, and at $z \sim 0.2$, is 1.5 to $5.3\,{\rm Gpc^{-3} yr^{-1}}$ (90\% c.l.); these bounds are model independent and a factor of $\sim 3$ tighter than that on the local rate of all BBH mergers, and hence are a robust constraint on all progenitor models. Including the events in our catalog increases the Fisher information about the BBH population by $\sim 47\%$, and tightens the constraints on population parameters.