Inferring eccentricity evolution from observations of coalescing binary black holes
Inferring eccentricity evolution from observations of coalescing binary black holes
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DOI：
10.1103/physrevd.107.064024
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发表时间：
2022-07
影响因子：
5
通讯作者：
A. Bonino;R. Gamba;P. Schmidt;A. Nagar;G. Pratten;M. Breschi;P. Rettegno;S. Bernuzzi
中科院分区：
文献类型：
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作者：
A. Bonino;R. Gamba;P. Schmidt;A. Nagar;G. Pratten;M. Breschi;P. Rettegno;S. Bernuzzi
恒星质量的双星黑洞的起源和形成仍然是一个悬而未决的问题，可以通过从它们的引力波信号中精确测量双星和轨道参数来解决。由于引力波的发射，这样的双星在接近合并时预计会变成圆形。然而，根据它们的形成通道，一些双星在进入当前引力波探测器的频带时可能具有不可忽略的偏心率。为了测量观测到的引力波信号的偏心率，描述偏心轨道上双星的精确波形模型是必要的。在这项工作中，我们证明了改进的TEOBResumS波形模型偏心聚结二进制对齐自旋的功效。我们首先验证模型对对准自旋二进制黑洞合并的模拟信号，并量化偏心率对其他内在的二进制参数的估计的影响。然后，我们进行了一个完全贝叶斯再分析的GW 150914偏心波形模型。我们发现：（i）该模型是可靠的对齐自旋的二元黑洞和（ii）GW 150914是一致的非偏心合并，虽然我们不能排除在参考频率为20 $ Hz的初始偏心率的小值。最后，我们提出了一个系统的方法来测量偏心率和它的演变直接从引力波后验样本。当比较来自不同分析的结果时，这种估计量是有用的，因为偏心率的定义在模型之间可能不同。我们的方案甚至可以应用在小偏心率的情况下，并且可以在后处理中直接采用，以允许模型之间的直接比较。
The origin and formation of stellar-mass binary black holes remains an open question that can be addressed by precise measurements of the binary and orbital parameters from their gravitational-wave signal. Such binaries are expected to circularize due to the emission of gravitational waves as they approach merger. However, depending on their formation channel, some binaries could have a non-negligible eccentricity when entering the frequency band of current gravitational-wave detectors. In order to measure eccentricity in an observed gravitational-wave signal, accurate waveform models that describe binaries in eccentric orbits are necessary. In this work we demonstrate the efficacy of the improved TEOBResumS waveform model for eccentric coalescing binaries with aligned spins. We first validate the model against mock signals of aligned-spin binary black hole mergers and quantify the impact of eccentricity on the estimation of other intrinsic binary parameters. We then perform a fully Bayesian reanalysis of GW150914 with the eccentric waveform model. We find (i) that the model is reliable for aligned-spin binary black holes and (ii) that GW150914 is consistent with a non-eccentric merger although we cannot rule out small values of initial eccentricity at a reference frequency of $20$ Hz. Finally, we present a systematic method to measure the eccentricity and its evolution directly from the gravitational-wave posterior samples. Such an estimator is useful when comparing results from different analyses as the definition of eccentricity may differ between models. Our scheme can be applied even in the case of small eccentricities and can be adopted straightforwardly in post-processing to allow for direct comparison between models.