Constraining the Inclinations of Binary Mergers from Gravitational-wave Observations
Constraining the Inclinations of Binary Mergers from Gravitational-wave Observations
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DOI：
10.3847/1538-4357/ab0b3e
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发表时间：
2018-09
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影响因子：
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通讯作者：
S. Usman;J. Mills;S. Fairhurst
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文献类型：
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作者：
S. Usman;J. Mills;S. Fairhurst
我们希望从致密双星的引力波特征中提取的大部分信息，只有在我们能够精确地限制轨道平面相对于视线的倾角时才能获得。在本文中，我们详细讨论了测量的二进制距离和倾斜，限制了我们的能力，准确地测量单独使用引力波的倾斜之间的简并。宇宙中事件的预期分布加剧了这种简并性，这导致我们更喜欢距离更远的面对面系统。我们使用一个简化的模型，只考虑二进制的距离和方向，并表明，这给出了可比的结果，从二进制中子星星合并GW 170817获得的完整的参数估计。对于先进的LIGO-Virgo网络，只有二进制文件接近边缘，即，倾斜度为<$75 °，这将与正面系统区分开。对两种引力波偏振都具有良好灵敏度的扩展网络只能将正面双星的倾角限制在20至1.45 °的信噪比。即使对于信噪比为100的响亮信号，正面信号也仅限于具有倾斜。在没有观测到的更高的模式或轨道进动，这种简并将主导在宇宙学距离的双黑洞合并的质量测量。
Much of the information we hope to extract from the gravitational-wave signatures of compact binaries is only obtainable when we can accurately constrain the inclination of the orbital plane relative to the line of sight. In this paper, we discuss in detail a degeneracy between the measurement of the binary distance and inclination that limits our ability to accurately measure the inclination using gravitational waves alone. This degeneracy is exacerbated by the expected distribution of events in the universe, which leads us to prefer face-on systems at a greater distance. We use a simplified model that only considers the binary distance and orientation and show that this gives comparable results to the full parameter estimates obtained from the binary neutron star merger GW170817. For the advanced LIGO-Virgo network, it is only binaries that are close to edge-on, i.e., with inclinations ι ≳ 75°, that will be distinguishable from face-on systems. Extended networks that have good sensitivity to both gravitational-wave polarizations will only be able to constrain the inclination of a face-on binary at a signal-to-noise ratio of 20 to ι ≲ 45°. Even for loud signals with signal-to-noise ratios of 100, face-on signals will only be constrained to have inclinations . In the absence of observable higher modes or orbital precession, this degeneracy will dominate the mass measurements of binary black hole mergers at cosmological distances.