A New Moment-Based General-Relativistic Neutrino-Radiation Transport Code: Methods and First Applications to Neutron Star Mergers
A New Moment-Based General-Relativistic Neutrino-Radiation Transport Code: Methods and First Applications to Neutron Star Mergers
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DOI：
10.1093/mnras/stac589
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发表时间：
2021-11
影响因子：
4.8
通讯作者：
D. Radice;S. Bernuzzi;A. Perego;R. Haas
中科院分区：
文献类型：
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作者：
D. Radice;S. Bernuzzi;A. Perego;R. Haas
提出了一个新的基于动量的能量积分中微子输运程序，用于广义相对论中子星星合并的模拟。在合并的情况下，我们是第一个代码，包括多普勒效应在所有的订单在100/c，保留所有非线性中微子物质耦合条款。该代码通过一系列严格的测试进行验证。我们表明，包括完整的中微子物质耦合条款是必要的，以正确地捕捉相对论运动介质中的中微子捕获，如在差分旋转合并残留物。我们进行初步的模拟证明了该计划在模拟从头合并黑洞崩溃和长期中子星星遗迹高达1070毫秒的鲁棒性。后者是最长的动态时空，3D，广义相对论模拟与全中微子运输日期。我们比较了在不同的分辨率和使用两种不同的时刻计划关闭获得的结果。我们没有发现显着的热力学平衡外的影响，如体积粘度，对合并后的动力学或引力波发射的证据。中微子光度和平均能量与理论预期和其他小组使用类似方案进行的先前模拟吻合良好。我们比较动力学和早期风喷出物与M1和我们的老中微子治疗。我们发现，M1的结果有系统地较大的质子分数。然而，核合成产率的差异是适度的。这项工作为未来更广泛的中微子反应、双星和状态方程的详细研究奠定了基础。
We present a new moment-based energy-integrated neutrino transport code for neutron star merger simulations in general relativity. In the merger context, ours is the first code to include Doppler effects at all orders in υ/c, retaining all nonlinear neutrino-matter coupling terms. The code is validated with a stringent series of tests. We show that the inclusion of full neutrino-matter coupling terms is necessary to correctly capture the trapping of neutrinos in relativistically moving media, such as in differentially rotating merger remnants. We perform preliminary simulations proving the robustness of the scheme in simulating ab-initio mergers to black hole collapse and long-term neutron star remnants up to ∼70 ms. The latter is the longest dynamical spacetime, 3D, general relativistic simulations with full neutrino transport to date. We compare results obtained at different resolutions and using two different closures for the moment scheme. We do not find evidences of significant out-of-thermodynamic equilibrium effects, such as bulk viscosity, on the postmerger dynamics or gravitational wave emission. Neutrino luminosities and average energies are in good agreement with theory expectations and previous simulations by other groups using similar schemes. We compare dynamical and early wind ejecta properties obtained with M1 and with our older neutrino treatment. We find that the M1 results have systematically larger proton fractions. However, the differences in the nucleosynthesis yields are modest. This work sets the basis for future detailed studies spanning a wider set of neutrino reactions, binaries and equations of state.