Precession during merger: Strong polarization changes are observationally accessible features of strong-field gravity during binary black hole merger
Precession during merger: Strong polarization changes are observationally accessible features of strong-field gravity during binary black hole merger
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合并期间的进动：强偏振变化是双黑洞合并期间强场引力的可观测特征
DOI：
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发表时间：
2012
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影响因子：
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通讯作者：
Georgia Tech
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作者：
R. O’Shaughnessy;L. London;J. Healy;D. S. U. O. Wisconsin;Center for Relativistic Astrophysics;Georgia Tech
来自紧密双星合并的短引力波信号将大量关于合并的强场动力学的信息编码成地面干涉仪可以访问的频率。在本文中，我们描述了一个以前未知的“岁差”的峰值发射方向与时间的合并之前和之后，总的角动量方向。我们证明，引力波偏振编码的方向，这个方向的视线。我们认为，极化的影响可以估计nonparametrically，直接从引力波信号看到沿着一条视线，作为一个缓慢变化的功能上的快速变化的载波。合并后，我们的结果可以被解释为一个相干激发的不同角度的准正规模式，叠加自然“旋进”和调制的视线振幅。最近的解析计算也得到了类似的几何解释。我们怀疑视线偏振的内容将是一个方便的可观察到的定义新的高精度测试的广义相对论使用引力波。此外，由于非线性合并过程种子的初始相干扰动，我们推测，这种影响的幅度提供了一个新的探测合并过程中的强场动力学。为了证明我们所描述的影响的普遍性，我们总结了104个通用进动二进制合并的合并后的演变。最后，我们提供了估计的可检测的影响，从高质量源的波形上的进动。这些表达式可以识别波形与现有样本不同的新的进动二进制参数。
The short gravitational wave signal from the merger of compact binaries encodes a surprising amount of information about the strong-field dynamics of merger into frequencies accessible to ground-based interferometers. In this paper we describe a previously unknown “precession” of the peak emission direction with time, both before and after the merger, about the total angular momentum direction. We demonstrate that the gravitational wave polarization encodes the orientation of this direction to the line of sight. We argue that the effects of polarization can be estimated nonparametrically, directly from the gravitational wave signal as seen along one line of sight, as a slowly varying feature on top of a rapidly varying carrier. After merger, our results can be interpreted as a coherent excitation of quasinormal modes of different angular orders, a superposition which naturally “precesses” and modulates the line-of-sight amplitude. Recent analytic calculations have arrived at a similar geometric interpretation. We suspect the line-of-sight polarization content will be a convenient observable with which to define new high-precision tests of general relativity using gravitational waves. Additionally, as the nonlinear merger process seeds the initial coherent perturbation, we speculate that the amplitude of this effect provides a new probe of the strong-field dynamics during merger. To demonstrate that the ubiquity of the effects we describe, we summarize the postmerger evolution of 104 generic precessing binary mergers. Finally, we provide estimates for the detectable impacts of precession on the waveforms from high-mass sources. These expressions may identify new precessing binary parameters whose waveforms are dissimilar from the existing sample.