Supernova Nucleosynthesis in Population III 13-50 M☉ Stars and Abundance Patterns of Extremely Metal-poor Stars
Supernova Nucleosynthesis in Population III 13-50 M☉ Stars and Abundance Patterns of Extremely Metal-poor Stars
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DOI：
10.1086/513063
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发表时间：
2007-01
期刊：
影响因子：
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通讯作者：
N. Tominaga;H. Umeda;K. Nomoto
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文献类型：
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作者：
N. Tominaga;H. Umeda;K. Nomoto
我们进行流体动力学和核合成计算的核心坍缩超新星（SNe）和超新星（HNe）的人口（Pop）III星。给出了新的主序质量MMS = 13-50 M，爆炸能量E =（1-40）× 10 ~（51）ergs，可用于化学演化研究。基于爆炸混合回退模型的HN产额再现了极贫金属（EMP）星（-4 < [Fe/H] < -3）的观测丰度模式，而极贫金属（VMP）星（-3 < [Fe/H] < -2）的HN产额则由Salpeter初始质量函数积分的正常SN产额再现。此外，观测到的EMP星丰度比[X/Fe]对[Fe/H]的小色散趋势可以再现为MMS和E的各种组合所产生的序列。这是因为我们采用了经验关系式，即更大质量的HNe会喷出更大量的Fe。我们的结果表明，观测到的小弥散趋势并不一定意味着早期银河系晕在[Fe/H] < -3时的快速均匀混合，而是可以用“非均匀”化学演化模型再现。此外，我们研究如何修改的电子摩尔分数叶和密度的分布在presupernova模型提高与观测的一致性。在这方面，我们讨论了中微子驱动的风和吸积盘的核合成的可能贡献。
We perform hydrodynamic and nucleosynthesis calculations of core-collapse supernovae (SNe) and hypernovae (HNe) of Population (Pop) III stars. We provide new yields for the main-sequence mass of MMS = 13-50 M☉ and the explosion energy of E = (1–40) × 1051 ergs to apply to chemical evolution studies. Our HN yields based on the mixing-fallback model of explosions reproduce the observed abundance patterns of extremely metal-poor (EMP) stars (-4 < [Fe/H] < -3), while those of very metal-poor (VMP) stars (-3 < [Fe/H] < -2) are reproduced by the normal SN yields integrated over the Salpeter initial mass function. Moreover, the observed trends of abundance ratios [X/Fe] against [Fe/H] with small dispersions for the EMP stars can be reproduced as a sequence resulting from the various combination of MMS and E. This is because we adopt the empirical relation that a larger amount of Fe is ejected by more massive HNe. Our results imply that the observed trends with small dispersions do not necessarily mean the rapid homogeneous mixing in the early Galactic halo at [Fe/H] < -3 but can be reproduced by the "inhomogeneous" chemical evolution model. In addition, we examine how the modifications of the distributions of the electron mole fraction Ye and the density in the presupernova models improve the agreement with observations. In this connection, we discuss possible contributions of nucleosynthesis in the neutrino-driven wind and the accretion disk.