Measuring the properties of nearly extremal black holes with gravitational waves
Measuring the properties of nearly extremal black holes with gravitational waves
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DOI：
10.1103/physrevd.98.044028
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发表时间：
2018-04
影响因子：
5
通讯作者：
K. Chatziioannou;G. Lovelace;M. Boyle;M. Giesler;D. Hemberger;R. Katebi;Lawrence E. Kidder;H. Pfeiffer;M. Scheel;B. Szil'agyi
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文献类型：
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作者：
K. Chatziioannou;G. Lovelace;M. Boyle;M. Giesler;D. Hemberger;R. Katebi;Lawrence E. Kidder;H. Pfeiffer;M. Scheel;B. Szil'agyi
描述黑洞的性质是引力波观测最重要的科学目标之一。天体物理学证据表明，接近极端的黑洞（即，自旋接近理论上限）可能存在，因此可能在引力波观测到的合并黑洞中。在本文中，我们探讨如何以及目前的引力波参数估计方法可以测量的自旋快速旋转的黑洞在双星。我们模拟引力波信号的数值相对论波形接近极端，合并黑洞。为了简单起见，我们只关注自旋与轨道角动量平行或反平行的双星。我们发现，恢复孔的近极端的自旋是具有挑战性的。当自旋接近极值并且彼此平行时，所得到的参数估计确实恢复了大的自旋，尽管恢复的自旋幅度仍然显著小于真实的自旋幅度。当自旋接近极值并且彼此反平行时，所得到的参数估计恢复了小的有效自旋，但错误地将各个自旋估计为接近零。我们研究了自旋先验的影响，并认为一个常用的先验（均匀的自旋大小和方向）阻碍了大黑洞自旋的无偏恢复。
Characterizing the properties of black holes is one of the most important science objectives for gravitational-wave observations. Astrophysical evidence suggests that black holes that are nearly extremal (i.e., spins near the theoretical upper limit) might exist and, thus, might be among the merging black holes observed with gravitational waves. In this paper, we explore how well current gravitational wave parameter estimation methods can measure the spins of rapidly spinning black holes in binaries. We simulate gravitational-wave signals using numerical-relativity waveforms for nearly-extremal, merging black holes. For simplicity, we confine our attention to binaries with spins parallel or antiparallel with the orbital angular momentum. We find that recovering the holes’ nearly extremal spins is challenging. When the spins are nearly extremal and parallel to each other, the resulting parameter estimates do recover spins that are large, though the recovered spin magnitudes are still significantly smaller than the true spin magnitudes. When the spins are nearly extremal and antiparallel to each other, the resulting parameter estimates recover the small effective spin but incorrectly estimate the individual spins as nearly zero. We study the effect of spin priors and argue that a commonly used prior (uniform in spin magnitude and direction) hinders unbiased recovery of large black-hole spins.