Analytic properties of the electromagnetic field of binary compact stars and electromagnetic precursors to gravitational waves
Analytic properties of the electromagnetic field of binary compact stars and electromagnetic precursors to gravitational waves
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DOI：
10.1093/ptep/ptaa126
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发表时间：
2020-08
影响因子：
3.5
通讯作者：
Tomoki Wada;M. Shibata;K. Ioka
中科院分区：
文献类型：
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作者：
Tomoki Wada;M. Shibata;K. Ioka
我们解析地研究了至少包含一颗中子星的紧密双星周围真空中的电磁场性质。我们证明了中子星的轨道运动在合并前引起了电磁场的高多极模式。这些模式叠加形成螺旋臂结构，其边缘可能是磁重联的位置。这些模式也使来自中子星双星的总坡印廷通量增加了2-4倍。我们还指出了由轨道运动引起的电场导致双星周围的磁层，并估计了其等离子体密度，该密度与Goldreich-Julian密度具有不同的参数依赖关系。有了这些特性，我们讨论了引力波事件可能的电磁对应物，并确定了射电前兆，如快速射电暴，作为最有希望的观测目标。
We analytically study the properties of the electromagnetic field in the vacuum around close binary compact stars containing at least one neutron star. We show that the orbital motion of the neutron star induces high multipole modes of the electromagnetic field just before the merger. These modes are superimposed to form a spiral arm configuration, and its edge is found to be a likely site for magnetic reconnection. These modes also enhance the total Poynting flux from neutron star binaries by a factor of 2–4. We also indicate that the electric field induced by the orbital motion leads to a magnetosphere around binaries and estimate its plasma density, which has a different parameter dependence than the Goldreich–Julian density. With these properties, we discuss possible electromagnetic counterparts to gravitational wave events, and identify radio precursors, such as fast radio bursts, as the most promising observational targets.