Modeling GW170817 based on numerical relativity and its implications
Modeling GW170817 based on numerical relativity and its implications
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DOI：
10.1103/physrevd.96.123012
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发表时间：
2017-12-22
影响因子：
5
通讯作者：
Tanaka, Masaomi
中科院分区：
文献类型：
--
作者：
Shibata, Masaru;Fujibayashi, Sho;Tanaka, Masaomi
引力波观测和大量的电磁观测表明，主要由先进的LIGO探测到的最新引力波事件GW170817的来源是一对中子星的合并。我们试图根据我们迄今为止进行的数值相对论模拟的结果来解释这一观测事件，特别注意光学和红外观测。我们最终得出的结论是，这一事件一致地描述了一个长寿命的超大质量或超大质量中子星作为合并遗迹的存在，因为(i)沿着我们的视线到这个源的镧系元素的严重污染可以通过它的强中微子辐射来避免，（ii）它可以在合并后阶段产生具有快速运动的可观质量的抛射成分中发挥关键作用。我们还指出(1)中子星状态方程必须足够坚硬（即冷球形中子星的最大质量M-max必须明显高于2 m -圆点），才能形成一颗长寿命的大质量中子星，作为GW170817双星系统的合并残余，其初始总质量大于或接近2.73 m -圆点；（II）与相对论性抛射相关的光学对应点的缺失表明M-max值不是很高，大约为2.15-2.25 m -圆点。
Gravitational-wave observation together with a large number of electromagnetic observations shows that the source of the latest gravitational-wave event, GW170817, detected primarily by advanced LIGO, is the merger of a binary neutron star. We attempt to interpret this observational event based on our results of numerical-relativity simulations performed so far, paying particular attention to the optical and infrared observations. We finally reach a conclusion that this event is described consistently by the presence of a long-lived hypermassive or supramassive neutron star as the merger remnant because (i) significant contamination by lanthanide elements along our line of sight to this source can be avoided by the strong neutrino irradiation from it and (ii) it could play a crucial role in producing an ejecta component of appreciable mass with fast motion in the postmerger phase. We also point out that (I) the neutron-star equation of state has to be sufficiently stiff (i.e., the maximum mass of cold spherical neutron stars, M-max, has to be appreciably higher than 2 M-circle dot) in order for a long-lived massive neutron star to be formed as the merger remnant for the binary systems of GW170817, for which the initial total mass is greater than or similar to 2.73 M-circle dot, and (II) the absence of optical counterparts associated with relativistic ejecta suggests a not-extremely-high value of M-max approximately as 2.15-2.25 M-circle dot.