Source Redshifts from Gravitational-Wave Observations of Binary Neutron Star Mergers
Source Redshifts from Gravitational-Wave Observations of Binary Neutron Star Mergers
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DOI：
10.1103/physrevx.4.041004
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发表时间：
2014-10-08
影响因子：
12.5
通讯作者：
Sathyaprakash, B. S.
中科院分区：
文献类型：
--
作者：
Messenger, C.;Takami, Kentaro;Sathyaprakash, B. S.
当我们进入引力波探测时代时，作为标准警报器的紧凑型双星将成为宇宙学的无价工具。然而，引力波携带的信息在静止坐标系总质量M和源的红移z之间的简并性意味着两者都不能直接从信号中提取;只有组合M（1 + z），即红移质量，可以直接从信号中提取。最近的工作表明，对于第三代探测器，潮汐校正的引力波相位的晚inspiral信号的双中子星星系统可以用来打破质量红移简并。在这里，我们建议使用的签名编码的合并后的信号，允许准确提取的固有的静止帧质量的源，反过来又允许确定源红移和光度距离。这种分析方法的全部内容以及由此导出的任何宇宙学推论都将完全从引力波观测中获得，因此将独立于宇宙学距离阶梯。使用不同质量的二进制中子星星合并的数值模拟，我们在不同的红移模型引力波信号，并使用贝叶斯参数估计，以确定的准确性，可以提取的红移和质量。我们发现，对于一个已知的中子星星状态方程，在爱因斯坦望远镜下，当红移z < 0.04时，红移的1 σ置信区间的中值相当于10%-20%的不确定度。
Inspiraling compact binaries as standard sirens will become an invaluable tool for cosmology when we enter the gravitational-wave detection era. However, a degeneracy in the information carried by gravitational waves between the total rest-frame mass M and the redshift z of the source implies that neither can be directly extracted from the signal; only the combination M(1 + z), the redshifted mass, can be directly extracted from the signal. Recent work has shown that for third-generation detectors, a tidal correction to the gravitational-wave phase in the late-inspiral signal of binary neutron star systems can be used to break the mass-redshift degeneracy. Here, we propose to use the signature encoded in the postmerger signal allowing the accurate extraction of the intrinsic rest-frame mass of the source, in turn permitting the determination of source redshift and luminosity distance. The entirety of this analysis method and any subsequent cosmological inference derived from it would be obtained solely from gravitational-wave observations and, hence, would be independent of the cosmological distance ladder. Using numerical simulations of binary neutron star mergers of different mass, we model gravitational-wave signals at different redshifts and use a Bayesian parameter estimation to determine the accuracy with which the redshift and mass can be extracted. We find that for a known illustrative neutron star equation of state and using the Einstein telescope, the median of the 1 sigma confidence regions in redshift corresponds to similar to 10%-20% uncertainties at redshifts of z < 0.04.