使用Spritz代码结合微观物理物态方程的双中子星并合模拟
Binary Neutron Star Merger Simulations with Microphysical Equation of State using Spritz
AI总结：
本研究使用GRMHD Spritz代码结合微观物态方程完成双中子星并合模拟，发现质量比影响并合后演化，等质量双星更易形成磁主导漏斗并产生准直外流，不等质量双星抛射质量更多但磁场放大较弱。
AI中文摘要：
我们首次使用广义相对论磁流体动力学（GRMHD）Spritz代码，结合有限温度表格物态方程完成双中子星并合模拟。选取两个磁化双星系统，采用LS220物态方程及类似GW170817的啁啾质量，仅质量比不同（q=1和q=0.7），模拟从晚期旋进阶段到并合、超大质量中子星（HMNS）形成，再到延迟坍缩为黑洞（BH）的全过程。我们研究双星质量比对并合后演化、喷流启动条件及物质抛射的影响。结果显示，等质量双星形成的HMNS寿命稍长，使并合后演化阶段的磁场放大更高效，因此积累了更大的磁通量，形成磁主导漏斗，并发射出准直的磁驱动极区外流。相比之下，不等质量双星抛射出的质量约多50%，但磁场放大较弱，极区在整个模拟过程中保持湍流且重子负载，表明磁主导漏斗的形成可能延迟。
英文摘要：
We present the first binary neutron star merger simulations performed with the general-relativistic magnetohydrodynamics (GRMHD) Spritz code employing a finite-temperature tabulated equation of state. Two magnetized binaries with the LS220 equation of state and a GW170817-like chirp mass, differing only in their mass ratios ($q=1$ and $q=0.7$), are evolved from the late inspiral through merger, hypermassive neutron-star (HMNS) formation, and delayed collapse to a black hole (BH). We investigate how the binary mass ratio influences the postmerger evolution, jet-launching conditions, and matter ejection. We find that the equal-mass binary forms a slightly longer-lived HMNS, allowing more efficient magnetic-field amplification during the post-merger evolution. As a result, it accumulates larger magnetic fluxes, develops a magnetically dominated funnel, and launches a collimated magnetically driven polar outflow. In contrast, the unequal-mass binary ejects approximately 50% more mass but exhibits weaker magnetic-field amplification, with the polar region remaining turbulent and baryon loaded throughout our simulation, suggesting that the development of a magnetically dominated funnel is likely delayed.
