Hydrodynamical Study of Neutrino-Driven Wind as an r-Process Site
Hydrodynamical Study of Neutrino-Driven Wind as an r-Process Site
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中微子驱动风作为 r 过程场的流体动力学研究
DOI：
10.1093/pasj/52.4.601
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发表时间：
1999
影响因子：
2.3
通讯作者：
S. Yamada
中科院分区：
文献类型：
--
作者：
K. Sumiyoshi;Hideyuki Suzuki;Kaori Otsuki;M. Terasawa;S. Yamada
基于广义相对论流体动力学模拟，讨论了原中子星星的中微子驱动风。我们研究了中微子驱动风的性质，以探索r过程核合成的可能性。利用质子中子星星的真实轮廓和简化模型，在中微子光度恒定的假设下，对中微子加热和冷却过程进行了数值模拟.系统地给出了PNS质量和中微子光度的关系。在以前的研究中的分析处理的比较。在现实PNS的情况下，我们发现在目前的假设下，每个重子的熵和膨胀时间尺度对于r过程来说既不高也不短。另一方面，我们还发现，由于我们对状态方程的适当处理，流体力学模拟得到的膨胀时间尺度比解析解有系统的缩短。这一事实可能会导致中子与种子比的增加，这是适合于中微子驱动n风中的r过程。事实上，在流体动力学模拟中，对于大质量、致密的高中微子光度原中子星，膨胀时标足够短，在r过程网络计算中产生了A ~ 200的r过程元.
We discuss the neutrino-driven wind from a proto-neutron star based on general-relat ivistic hydrodynamical simulations. We examine the properties of the neutrino-driven wind to explore the possibility of r-process nucleosynthesis. Numerical simulations involving neutrino heating and cooling processes were performed with the assumption of a constant neutrino luminosity by using realistic profiles of the protoneutron star (PNS) as well as simplified models. The dependence on the mass of PNS and the neutrino luminosity is presented systematically. Comparisons with analytic treatments in the previous studies are also given. In the cases with the realistic PNS, we have found that the entropy per baryon and the expansion time scale are neither high nor short enough for the r-process within the current assumptions. On the other hand, we have also found that the expansion time scale obtained by hydrodynamica l simulations is systematically shorter than that in the analytic solutions due to our proper treatment of the equation of state. This fact might lead to an increase in the neutron-to-seed ratio, which is suitable for the r-process in a neutrino-drive n wind. Indeed, in the case of massive and compact proto-neutron stars with high neutrino luminosities, the expansion time scale is found to be sufficiently short in hydrodynamica l simulations, and the r-process elements up to A ~ 200 are produced in the r-process network calculation.