Unequal mass binary neutron star simulations with neutrino transport: Ejecta and neutrino emission
Unequal mass binary neutron star simulations with neutrino transport: Ejecta and neutrino emission
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DOI：
10.1103/physrevd.101.044053
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发表时间：
2019-08
影响因子：
5
通讯作者：
Trevor Vincent;F. Foucart;Matthew D. Duez;R. Haas;Lawrence E. Kidder;H. Pfeiffer;M. Scheel
中科院分区：
文献类型：
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作者：
Trevor Vincent;F. Foucart;Matthew D. Duez;R. Haas;Lawrence E. Kidder;H. Pfeiffer;M. Scheel
我们提出了12个新的模拟不等质量中子星星合并。模拟进行了SpEC代码，并利用基于核理论的状态方程和两个时刻的灰中微子输运计划与改进的能量估计的基础上发展的数密度。我们模拟的中子星与SFHo，LS 220和DD 2状态方程（EOS），我们研究了中微子和物质的排放所有12个模型，以寻找强大的趋势之间的二进制参数和排放特性。我们发现，动态喷出物的总质量超过$0.01M_\odot$只有SFHo的质量比在所有模型的弱依赖。我们发现，喷出物具有宽的电子分数（$Y_e$）分布（$\approximat0.06 -0.48$），平均$0.2$。$Y_e$随中微子辐照时间的增加而增加，但随二元不对称性的增加而减小。我们还发现，该模型具有广泛的渐近速度分布（约0.05-0.7c$）的喷出物。平均速度在0.2c- 0.3c的范围内，并随着二元不对称性而减小。此外，我们发现，磁盘的质量增加的二元不对称性和刚度的状态方程。圆盘的$Y_e$随着EOS的软度而增加。最强的中微子发射发生在软状态方程模型中。对于（反）电子中微子，我们没有发现显着的大小或角分布或中微子光度与质量比的依赖关系。较重的中微子种类的光度依赖于质量比，但角分布不随质量比而改变。
We present twelve new simulations of unequal mass neutron star mergers. The simulations were preformed with the SpEC code, and utilize nuclear-theory based equations of state and a two-moment gray neutrino transport scheme with an improved energy estimate based on evolving the number density. We model the neutron stars with the SFHo, LS220 and DD2 equations of state (EOS) and we study the neutrino and matter emission of all twelve models to search for robust trends between binary parameters and emission characteristics. We find that the total mass of the dynamical ejecta exceeds $0.01M_\odot$ only for SFHo with weak dependence on the mass-ratio across all models. We find that the ejecta have a broad electron fraction ($Y_e$) distribution ($\approx 0.06-0.48$), with mean $0.2$. $Y_e$ increases with neutrino irradiation over time, but decreases with increasing binary asymmetry. We also find that the models have ejecta with a broad asymptotic velocity distribution ($\approx 0.05-0.7c$). The average velocity lies in the range $0.2c - 0.3c$ and decreases with binary asymmetry. Furthermore, we find that disk mass increases with binary asymmetry and stiffness of the EOS. The $Y_e$ of the disk increases with softness of the EOS. The strongest neutrino emission occurs for the models with soft EOS. For (anti) electron neutrinos we find no significant dependence of the magnitude or angular distribution or neutrino luminosity with mass-ratio. The heavier neutrino species have a luminosity dependence on mass-ratio but an angular distribution which does not change with mass-ratio.