Bayesian statistical framework for identifying strongly lensed gravitational-wave signals
Bayesian statistical framework for identifying strongly lensed gravitational-wave signals
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DOI：
10.1103/physrevd.107.123015
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发表时间：
2021-04
影响因子：
5
通讯作者：
R. K. Lo;I. Magaña Hernandez
中科院分区：
文献类型：
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作者：
R. K. Lo;I. Magaña Hernandez
与电磁波类似，引力波可以通过干涉物质被引力透镜化，与未被透镜化的信号相比，在不同的视光度距离上产生相同信号的多个实例，在不同的时间到达，具有不同的相移。如果没有解释，这些透镜信号将伪装成独立的系统，具有更高的质量和更低的红移。在这里，我们提出了一个贝叶斯统计框架，用于识别包含天体物理信息和选择效应的强透镜引力波信号。我们还提出了一种两步层次分析，以更有效地计算不受透镜引入的偏差影响的源参数的概率和推断。我们用例子来说明改变天体物理模型如何改变人们对观测到的引力波起源的解释，并可能得出观测到的引力波存在强透镜效应的无可争辩的证据。此外，我们还演示了在透镜信号源的天空定位方面的改进，以及在某些情况下透镜信号的莫尔斯指数的识别。如果得到证实，透镜引力波将使我们能够以更高的红移探测宇宙，并用更少的探测器约束引力波的极化内容。
It is expected that gravitational waves, similar to electromagnetic waves, can be gravitationally lensed by intervening matters, producing multiple instances of the same signal arriving at different times from different apparent luminosity distances with different phase shifts compared to the un-lensed signal due to lensing. If unaccounted for, these lensed signals will masquerade as separate systems with higher mass and lower redshift. Here we present a Bayesian statistical framework for identifying strongly-lensed gravitational-wave signals that incorporates astrophysical information and accounts for selection effects. We also propose a two-step hierarchical analysis for more efficient computations of the probabilities and inferences of source parameters free from bias introduced by lensing. We show with examples on how changing the astrophysical models could shift one's interpretation on the origin of the observed gravitational waves, and possibly lead to indisputable evidence of strong lensing of the observed waves. In addition, we demonstrate the improvement in the sky localization of the source of the lensed signals, and in some cases the identification of the Morse indices of the lensed signals. If confirmed, lensed gravitational waves will allow us to probe the Universe at higher redshift, and to constrain the polarization contents of the waves with fewer detectors.