Spectral properties of the post-merger gravitational-wave signal from binary neutron stars
Spectral properties of the post-merger gravitational-wave signal from binary neutron stars
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DOI：
10.1103/physrevd.91.064001
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发表时间：
2014-12
影响因子：
5
通讯作者：
K. Takami;L. Rezzolla;L. Baiotti
中科院分区：
文献类型：
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作者：
K. Takami;L. Rezzolla;L. Baiotti
在一些作者以前工作的基础上，我们最近提出了一种新的方法，其中来自合并的中子星双星的引力波的探测可以用来确定核密度下的物质状态方程，从而确定中子星的结构。特别是，在用核状态方程对双星进行了大量的数值相对论模拟后，我们发现合并后的发射具有两个明显且稳健的光谱特征。虽然高频峰值已经被证明与合并产生的超大质量中子星的振荡有关，并取决于状态方程，但我们强调了低频峰值与合并过程和双星中恒星的总致密性有关。这种关系本质上是普遍的，并提供了一个强大的工具来对状态方程设置严格的约束。我们在这里提供更多关于所进行的广泛分析的信息，说明所使用的方法、所考虑的测试以及结果的稳健性。我们还讨论了在探索数据时可以推导出的附加关系，以及这些关系如何与双星的各种属性相关。最后，我们给出了一个简单的机械玩具模型，它解释了合并后信号的主要频谱特征，甚至可以解析地再现合并后立即发出的复杂波形。
Extending previous work by a number of authors, we have recently presented a new approach in which the detection of gravitational waves from merging neutron star binaries can be used to determine the equation of state of matter at nuclear density and hence the structure of neutron stars. In particular, after performing a large number of numerical-relativity simulations of binaries with nuclear equations of state, we have found that the post-merger emission is characterized by two distinct and robust spectral features. While the high-frequency peak was already shown to be associated with the oscillations of the hypermassive neutron star produced by the merger and to depend on the equation of state, we have highlighted that the low-frequency peak is related to the merger process and to the total compactness of the stars in the binary. This relation is essentially universal and provides a powerful tool to set tight constraints on the equation of state. We here provide additional information on the extensive analysis performed, illustrating the methods used, the tests considered, as well as the robustness of the results. We also discuss additional relations that can be deduced when exploring the data and how these correlate with various properties of the binary. Finally, we present a simple mechanical toy model that explains the main spectral features of the post-merger signal and can even reproduce analytically the complex waveforms emitted right after the merger.