Neutrino emission from binary neutron star mergers: characterising light curves and mean energies
Neutrino emission from binary neutron star mergers: characterising light curves and mean energies
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DOI：
10.1140/epja/s10050-022-00743-5
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发表时间：
2021-11
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影响因子：
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通讯作者：
M. Cusinato;F. Guercilena;A. Perego;D. Logoteta;D. Radice;S. Bernuzzi;S. Ansoldi
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文献类型：
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作者：
M. Cusinato;F. Guercilena;A. Perego;D. Logoteta;D. Radice;S. Bernuzzi;S. Ansoldi
中子星星的合并会释放出大量的中微子，这是因为在合并过程中以及合并之后，致密物质会达到高温。中微子影响合并动力学和形状的喷出物的属性，包括resultingr-process核合成和kilonova排放。在这项工作中，我们分析了中微子发射从一个大样本的二元中子星星合并模拟的数值相对论，涵盖了广泛的初始质量，核状态方程和粘度处理。我们提取中微子光度和平均能量，并计算感兴趣的数量，如峰值，峰宽，时间平均值和减少时间尺度。我们提供了一个系统的描述，这些数量，包括它们对系统的初始参数的依赖。我们发现，对于等质量系统的总中微子光度（几个）减少潮汐变形能力的增加，作为一个结果，不太激烈的合并动力学。类似地，不对称合并中的潮汐扰动导致系统性较小的光度。峰值亮度可以是平均亮度的两倍。电子反中微子的光度在电子中微子中占主导地位（最初是2-3倍），而电子中微子和重味中微子的光度相似。平均能量几乎是恒定的时间和独立的二进制参数。它们的值反映了合并残余物内部不同的退耦温度。尽管目前的中微子模型的不确定性，我们的研究结果提供了一个广泛的和物理接地特性的中微子发射，他们可以作为一个参考点，开发更复杂的中微子运输计划。
Neutrinos are copiously emitted by neutron star mergers, due to the high temperatures reached by dense matter during the merger and its aftermath. Neutrinos influence the merger dynamics and shape the properties of the ejecta, including the resultingr-process nucleosynthesis and kilonova emission. In this work, we analyse neutrino emission from a large sample of binary neutron star merger simulations in Numerical Relativity, covering a broad range of initial masses, nuclear equation of state and viscosity treatments. We extract neutrino luminosities and mean energies, and compute quantities of interest such as the peak values, peak broadnesses, time averages and decrease time scales. We provide a systematic description of such quantities, including their dependence on the initial parameters of the system. We find that for equal-mass systems the total neutrino luminosity (several) decreases as the reduced tidal deformability increases, as a consequence of the less violent merger dynamics. Similarly, tidal disruption in asymmetric mergers leads to systematically smaller luminosities. Peak luminosities can be twice as large as the average ones. Electron antineutrino luminosities dominate (initially by a factor of 2-3) over electron neutrino ones, while electron neutrinos and heavy flavour neutrinos have similar luminosities. Mean energies are nearly constant in time and independent on the binary parameters. Their values reflect the different decoupling temperature inside the merger remnant. Despite present uncertainties in neutrino modelling, our results provide a broad and physically grounded characterisation of neutrino emission, and they can serve as a reference point to develop more sophisticated neutrino transport schemes.