Constraining the orbital eccentricity of inspiralling compact binary systems with Advanced LIGO
Constraining the orbital eccentricity of inspiralling compact binary systems with Advanced LIGO
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DOI：
10.1103/physrevd.105.023003
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发表时间：
2021-08
影响因子：
5
通讯作者：
Marc Favata;Chunglee Kim;K. Arun;JeongCho Kim;H. Lee
中科院分区：
文献类型：
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作者：
Marc Favata;Chunglee Kim;K. Arun;JeongCho Kim;H. Lee
使用高级 LIGO 和 Virgo 探测器检测到约 50 个合并致密双星，使我们能够测试广义相对论、限制合并率，并寻找潮汐效应、致密天体自旋、更高波形模式和黑洞振铃的证据。尚未可靠地检测到的一个效应是双星偏心率，它可能存在于动态形成的双星的一小部分中。在这里，我们讨论偏心率的一般限制，原则上，可以通过在高级 LIGO 的设计灵敏度下运行的探测器对所有类型的致密天体双星施加限制。使用在小偏心率范围内有效的后牛顿引力波定相模型，我们评估了各种旋转和非旋转双星的偏心率的相对测量误差。还研究了涉及质量和自旋参数的误差和相关性。我们发现，降低探测器观测频带的低频限制是增加测量二元偏心率的几率的关键设计因素之一。我们还介绍并分析探索了偏心线性调频质量参数，该参数取代线性调频质量作为偏心引力波形模型中的关键可测量参数组合。偏心线性调频质量参数解释了线性调频质量和偏心率之间的简并性。这种简并性导致标准线性调频脉冲质量参数出现偏差。我们还研究了使用圆形波形模板恢复偏心系统时出现的系统参数偏差。我们使用 Fisher 矩阵和基于贝叶斯推理的马尔可夫链蒙特卡罗 (MCMC) 方法来研究这些参数估计问题，并且我们发现在适当的信噪比范围内，两种方法（统计误差和系统误差）之间具有良好的一致性。这项研究有助于量化使用偏心率测量作为双星形成通道探针的有效性。
The detection of ∼ 50 coalescing compact binaries with the Advanced LIGO and Virgo detectors has allowed us to test general relativity, constrain merger rates, and look for evidence of tidal effects, compact object spins, higher waveform modes, and black hole ringdowns. An effect that has not yet been confidently detected is binary eccentricity, which might be present in a small fraction of binaries formed dynamically. Here we discuss general limits on eccentricity that can, in-principle, be placed on all types of compact object binaries by a detector operating at the design sensitivity of Advanced LIGO. Using a post-Newtonian model for gravitational-wave phasing valid in the small eccentricity regime, we assess the relative measurement error for eccentricity for a variety of spinning and non-spinning binaries. Errors and correlations involving the mass and spin parameters are also investigated. We find that decreasing the low frequency limit of a detector’s observational frequency band is one of the key design factors for increasing the odds of measuring binary eccentricity. We also introduce and analytically explore the eccentric chirp mass parameter, which replaces the chirp mass as the key measurable parameter combination in eccentric gravitational waveform models. The eccentric chirp mass parameter explains a degeneracy between the chirp mass and the eccentricity. This degeneracy leads to a bias in the standard chirp mass parameter. We also investigate the systematic parameter bias that arises when eccentric systems are recovered using circular waveform templates. We use both Fisher matrix and Bayesian-inference-based Markov Chain Monte Carlo (MCMC) methods to investigate these parameter estimation issues, and we find good agreement between the two approaches (for both statistical and systematic errors) in the appropriate signal-to-noise ratio regime. This study helps to quantify how effectively one can use eccentricity measurements as a probe of binary formation channels.