论文标题
二进制黑洞的低有效自旋及其对单个重力波事件的影响
The Low Effective Spin of Binary Black Holes and Implications for Individual Gravitational-Wave Events
论文作者
论文摘要
现在，先进的Ligo和处女座重力波实验定期观察到二进制黑洞合并，但这些事件的进化起源仍然是一个谜。对二进制黑洞旋转分布的分析可能会揭示出这个谜团，从而提供了一种区分不同二进制形成通道的方法。利用来自Advanced Ligo和处女座的第一和第二观测运行的数据，我们试图仔细地表征有效自旋在二进制黑洞之间的分布，从层次上测量分布的平均$μ$和方差$σ^2 $，同时考虑选择效果以及在旋转和其他黑洞参数之间进行选择效果和脱发。我们证明，已知的二进制黑孔的群体的旋转都很小，$μ\ sim 0 $，并且非常狭窄，分布非常狭窄，$σ^2 \ leq 0.07 $，可信度为95％。然后，我们探讨了这些合奏特性所暗示的关于单个二进制黑洞合并的旋转，从而将现有的重力波事件重新分析，并在其有效旋转方面具有人口信息。以前排除的有效旋转等于零的二进制黑洞GW170729现在与左有效自旋一致，以〜10％的信誉。更广泛地说，我们发现非信息性旋转先验通常会产生高估的紧凑型二进制合并的有效自旋幅度。
While the Advanced LIGO and Virgo gravitational-wave experiments now regularly observe binary black hole mergers, the evolutionary origin of these events remains a mystery. Analysis of the binary black hole spin distribution may shed light on this mystery, offering a means of discriminating between different binary formation channels. Using the data from Advanced LIGO and Virgo's first and second observing runs, here we seek to carefully characterize the distribution of effective spin among binary black holes, hierarchically measuring the distribution's mean $μ$ and variance $σ^2$ while accounting for selection effects and degeneracies between spin and other black hole parameters. We demonstrate that the known population of binary black holes have spins that are both small, with $μ\sim 0$, and very narrowly distributed, with $σ^2 \leq 0.07$ at 95% credibility. We then explore what these ensemble properties imply about the spins of individual binary black hole mergers, re-analyzing existing gravitational-wave events with a population-informed prior on their effective spin. The binary black hole GW170729, which previously excluded effective spin equal to zero, is now consistent with zero effective spin at ~10% credibility. More broadly, we find that uninformative spin priors generally yield overestimates for the effective spin magnitudes of compact binary mergers.
