Determination of properties of protoneutron stars toward black hole formation via gravitational wave observations
Determination of properties of protoneutron stars toward black hole formation via gravitational wave observations
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通过引力波观测确定原中子星对黑洞形成的特性
DOI：
10.1103/physrevd.100.083008
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发表时间：
2019
影响因子：
5
通讯作者：
Sumiyoshi Kohsuke
中科院分区：
文献类型：
--
作者：
Sotani Hajime;Sumiyoshi Kohsuke
我们研究了从吸积质子中子星到黑洞形成过程中引力波的基模和引力模的频率。为此目的，我们分析了两种不同的祖星的引力坍缩的三个状态方程的数值结果。采用球对称下广义相对论中微子辐射流体力学数值模拟得到的中心天体轮廓。利用相对论Cowling近似，在每个时间步，将一系列快照作为静态位形，求解本征值问题，确定了从核反弹到黑洞形成过程中吸积作用下演化的PNS引力波的特定频率.我们发现，模式引力波的频率可以表示为PNS在每个时间步的平均密度的函数几乎独立于祖模型，与以前的研究普通PNS雅阁。我们还发现，模式频率的模式频率的比例是不敏感的祖先，但强烈依赖于紧凑的PNS。同时观测PNS的模和模引力波，可以获得PNS的平均密度和致密性信息，从而重建PNS的质量和半径演化，作为高密度状态方程的约束条件。此外，我们表明，最大质量的PNS的最高平均密度可以估计与模式的引力波的检测与中微子观测的帮助。
We examine the frequencies of the fundamental () and the gravity () mode in gravitational waves from accreting protoneutron stars (PNSs) toward black hole formation. For this purpose, we analyze numerical results of gravitational collapse of massive stars for two different progenitors with three equations of state. We adopt profiles of central objects obtained from the numerical simulations by solving general relativistic neutrino-radiation hydrodynamics under the spherical symmetry. Using a series of snapshots as a static configuration at each time step, we solve the eigenvalue problem to determine the specific frequencies of gravitational waves from the evolving PNSs with accretion from core bounce to black hole formation by the relativistic Cowling approximation. We find that the frequency of the-mode gravitational waves can be expressed as a function of the average density of the PNS at each time step almost independently of the progenitor models in accord with the previous studies on ordinary PNSs. We also find that the ratio of the-mode frequency to the-mode frequency is insensitive to the progenitor but strongly depends on the compactness of the PNSs. Having a simultaneous observation of the- and-mode gravitational waves, it would provide the information of the average density and compactness of PNS, which can reconstruct the evolution of mass and radius of the PNSs as a constraint on the equation of state at high densities. Furthermore, we show that the highest average density of the PNS with the maximum mass can be estimated with the detection of the-mode gravitational waves together with the help of the neutrino observations.