Electromagnetic precursor flares from the late inspiral of neutron star binaries
Electromagnetic precursor flares from the late inspiral of neutron star binaries
复制标题
DOI：
10.1093/mnras/stac1909
复制
发表时间：
2022-05
影响因子：
4.8
通讯作者：
E. Most;A. Philippov
中科院分区：
文献类型：
--
作者：
E. Most;A. Philippov
两颗中子星的合并伴随着引力波的发射，也可能是由质量抛射提供动力的电磁对应物，以及合并后形成的相对论喷流。由于中子星可以以强磁场为特征，中子星磁层之间的非平凡相互作用可能会在合并之前助长潜在的强大电磁瞬变。为这些前兆瞬变提供能量的一个关键过程是在两颗恒星之间形成的强电流片中的相对论重联。在这项工作中，我们详细分析了双星共同磁层的扭曲如何导致电磁耀斑的发射，类似于在太阳日冕中产生的电磁耀斑。通过相对论无力电动力学模拟，我们阐明了不同的磁场拓扑在这一过程中的作用。我们的结论是，除非其中一颗中子星的磁场明显弱于另一颗，否则在适当的磁场排列下，总会发生耀斑。
The coalescence of two neutron stars is accompanied by the emission of gravitational waves, and can also feature electromagnetic counterparts powered by mass ejecta and the formation of a relativistic jet after the merger. Since neutron stars can feature strong magnetic fields, the non-trivial interaction of the neutron star magnetospheres might fuel potentially powerful electromagnetic transients prior to merger. A key process powering those precursor transients is relativistic reconnection in strong current sheets formed between the two stars. In this work, we provide a detailed analysis of how the twisting of the common magnetosphere of the binary leads to an emission of electromagnetic flares, akin to those produced in the solar corona. By means of relativistic force-free electrodynamics simulations, we clarify the role of different magnetic field topologies in the process. We conclude that flaring will always occur for suitable magnetic field alignments, unless one of the neutron stars has a magnetic field significantly weaker than the other.