Numerical relativity simulations of precessing binary neutron star mergers
Numerical relativity simulations of precessing binary neutron star mergers
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DOI：
10.1103/physrevd.97.064002
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发表时间：
2017-12
影响因子：
5
通讯作者：
T. Dietrich;S. Bernuzzi;B. Bruegmann;M. Ujevic;W. Tichy
中科院分区：
文献类型：
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作者：
T. Dietrich;S. Bernuzzi;B. Bruegmann;M. Ujevic;W. Tichy
我们给出了第一组包含自旋进动效应并以多分辨率演化的二元中子合并的数值相对论模拟。我们的模拟使用了广义相对论中一致的初始数据，具有不同的自旋构型和无量纲自旋幅度$\sim 0.1$。它们以引力波频率$392$~HZ开始，覆盖了超过$1$的进动周期和大约15个轨道直到合并。我们通过分析坐标轨迹、准局域自旋测量和能量学，通过比较自旋排列、反排列和无旋组态，讨论了自旋进动动力学。通过计算不同自旋构型的引力波在末期的失配，对不同自旋构型的引力波进行了比较。我们发现，对于近似面对面的双星，进动效应与自旋对齐的非进动组态是不可区分的，而后者与非自旋组态是不同的。相反，自旋进动效应对于近边双星是清晰可见的。对于所考虑的参数，岁差对合并后的特征引力波频率和质量抛射没有显著影响。我们的结果为模拟双中子星事件引力波中的自旋进动效应奠定了基础。
We present the first set of numerical relativity simulations of binary neutron mergers that include spin precession effects and are evolved with multiple resolutions. Our simulations employ consistent initial data in general relativity with different spin configurations and dimensionless spin magnitudes $\sim 0.1$. They start at a gravitational-wave frequency of $\sim392$~Hz and cover more than $1$ precession period and about 15 orbits up to merger. We discuss the spin precession dynamics by analyzing coordinate trajectories, quasi-local spin measurements, and energetics, by comparing spin aligned, antialigned, and irrotational configurations. Gravitational waveforms from different spin configuration are compared by calculating the mismatch between pairs of waveforms in the late inspiral. We find that precession effects are not distinguishable from nonprecessing configurations with aligned spins for approximately face-on binaries, while the latter are distinguishable from a nonspinning configurations. Spin precession effects are instead clearly visible for approximately edge-on binaries. For the parameters considered here, precession does not significantly affect the characteristic postmerger gravitational-wave frequencies nor the mass ejection. Our results pave the way for the modeling of spin precession effects in the gravitational waveform from binary neutron star events.