Gravitational-wave signal from binary neutron stars: A systematic analysis of the spectral properties
Gravitational-wave signal from binary neutron stars: A systematic analysis of the spectral properties
复制标题
DOI：
10.1103/physrevd.93.124051
复制
发表时间：
2016-04
影响因子：
5
通讯作者：
L. Rezzolla;K. Takami
中科院分区：
文献类型：
--
作者：
L. Rezzolla;K. Takami
大量的工作表明，从合并中子星双星发射的引力波中可以提取出关于核密度下物质状态方程的重要信息。本文对56颗中子星双星在旋进、合并和合并后的引力波信号进行了全面的分析。这个双星样本可以说是迄今为止用现实状态方程研究的最大样本，跨越了六个不同的核物理状态方程和十个质量，使我们能够锐化最近获得的关于引力波信号光谱特性的一些结果。总体而言，我们发现：（1）对于质量相差不超过20的双星，引力波振幅最大值处的频率与两星的潮汐形变准普适地相关，（2）光谱特性在合并后阶段发生变化，在合并后的几毫秒内有一个过渡阶段，随后是一个准稳定阶段;（iii）当区分这两个相位之间的谱峰时，在谱峰识别中的一些模糊性消失，留下简单而鲁棒的图像;（iv）使用适当识别的频率，发现中子星的谱特征和性质之间的准普适关系;（v）对于最显著的峰，可以根据恒星潮汐变形性或紧度得到解析拟合函数。总之，这些结果支持了这样的想法，即核物质的状态方程可以严格约束时，在引力波信号从双中子星被检测到。
A number of works have shown that important information on the equation of state of matter at nuclear density can be extracted from the gravitational waves emitted by merging neutron-star binaries. We present a comprehensive analysis of the gravitational-wave signal emitted during the inspiral, merger and post-merger of 56 neutron-star binaries. This sample of binaries, arguably the largest studied to date with realistic equations of state, spans across six different nuclear-physics equations of state and ten masses, allowing us to sharpen a number of results recently obtained on the spectral properties of the gravitational-wave signal. Overall we find that: (i) for binaries with masses differing no more than $20\%$, the frequency at gravitational-wave amplitude's maximum is related quasi-universally with the tidal deformability of the two stars; (ii) the spectral properties vary during the post-merger phase, with a transient phase lasting a few millisecond after the merger and followed by a quasi-stationary phase; (iii) when distinguishing the spectral peaks between these two phases, a number of ambiguities in the identification of the peaks disappear, leaving a simple and robust picture; (iv) using properly identified frequencies, quasi-universal relations are found between the spectral features and the properties of the neutron stars; (v) for the most salient peaks analytic fitting functions can be obtained in terms of the stellar tidal deformability or compactness. Altogether, these results support the idea that the equation of state of nuclear matter can be constrained tightly when a signal in gravitational waves from binary neutron stars is detected.