Binary Neutron Star Mergers: Mass Ejection, Electromagnetic Counterparts, and Nucleosynthesis
Binary Neutron Star Mergers: Mass Ejection, Electromagnetic Counterparts, and Nucleosynthesis
复制标题
DOI：
10.3847/1538-4357/aaf054
复制
发表时间：
2018-09
期刊：
影响因子：
--
通讯作者：
D. Radice;A. Perego;K. Hotokezaka;S. Fromm;S. Bernuzzi;L. Roberts
中科院分区：
文献类型：
--
作者：
D. Radice;A. Perego;K. Hotokezaka;S. Fromm;S. Bernuzzi;L. Roberts
我们对双中子星（NS）合并中的质量抛射以及相关的电磁瞬变和核合成进行了系统的数值相对论研究。我们发现一些 10−3 M⊙ 的物质在合并过程中被动态喷射出来。这些流出的数量和性质取决于二元参数和 NS 状态方程 (EOS)。这些喷射物的一小部分，通常为∼10−6 M⊙，被合并后不久形成的冲击波加速至大于0.6c的速度，并在合并后数周、数月或数年的时间尺度上产生明亮的射电耀斑。他们的观察可能会限制 NS 合并后反弹的强度，从而限制极端密度下物质的 EOS。动态喷射物强烈地产生第二和第三r过程峰值核，其相对同位素丰度接近太阳。相反，轻r过程元素的生产对二元质量比和中微子辐射处理很敏感。合并后会形成高达 ∼0.2 M⊙ 的吸积盘，具体取决于残余物的寿命。在大多数情况下，来自这些圆盘的中微子和粘性驱动的风主导了总体流出量。最后，我们生成合成的千新星光变曲线，发现千新星取决于合并结果，可以用来约束 NS EOS。
We present a systematic numerical relativity study of the mass ejection and the associated electromagnetic transients and nucleosynthesis from binary neutron star (NS) mergers. We find that a few 10−3 M⊙ of material is ejected dynamically during the mergers. The amount and the properties of these outflows depend on binary parameters and on the NS equation of state (EOS). A small fraction of these ejecta, typically ∼10−6 M⊙, is accelerated by shocks formed shortly after merger to velocities larger than 0.6c and produces bright radio flares on timescales of weeks, months, or years after merger. Their observation could constrain the strength with which the NSs bounce after merger and, consequently, the EOS of matter at extreme densities. The dynamical ejecta robustly produce second and third r-process peak nuclei with relative isotopic abundances close to solar. The production of light r-process elements is instead sensitive to the binary mass ratio and the neutrino radiation treatment. Accretion disks of up to ∼0.2 M⊙ are formed after merger, depending on the lifetime of the remnant. In most cases, neutrino- and viscously driven winds from these disks dominate the overall outflow. Finally, we generate synthetic kilonova light curves and find that kilonovae depend on the merger outcome and could be used to constrain the NS EOS.