Nucleosynthesis of Zinc and Iron Peak Elements in Population III Type II Supernovae: Comparison with Abundances of Very Metal Poor Halo Stars
Nucleosynthesis of Zinc and Iron Peak Elements in Population III Type II Supernovae: Comparison with Abundances of Very Metal Poor Halo Stars
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DOI：
10.1086/323946
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发表时间：
2001-03
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影响因子：
--
通讯作者：
H. Umeda;K. Nomoto
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作者：
H. Umeda;K. Nomoto
我们计算了大质量第III族恒星核坍缩爆炸的核合成，并将计算结果与贫金属晕星的丰度进行了比较，以约束第III族超新星的参数。我们专注于铁峰元素，特别是，我们试图重现大[Zn/Fe]观察到的极端贫金属恒星。观察到的比值[Zn，Co，Mn，Cr，V/Fe]的有趣趋势与超新星喷出物中完全和不完全Si燃烧区的相对质量的变化有关。我们发现，[Zn/Fe]是更大的更深的质量削减，更小的中子过剩，和更大的爆炸能量。在贫金属晕星中观察到的大[Zn/Fe]和[O/Fe]表明完整的Si燃烧物质的深度混合和II型超新星中大量的回落。此外，需要大的爆炸能量（对于M ~ 13 M的当量为E51 <$2，对于M ~ 20 M的当量为E51 <$20）来再生[Zn/Fe] ~ 0.5。观测到的铁峰元素之间的丰度比的趋势更好地解释与这种高能量（“超新星”）模型比简单的“深”质量削减效应，因为过量的镍可以避免在超新星模型。我们还给出了M <$130 -300 M的对不稳定性超新星爆炸的产额，并讨论了对不稳定性超新星不能解释非常贫金属星的丰度特征。
We calculate nucleosynthesis in core collapse explosions of massive Population III stars and compare the results with abundances of metal-poor halo stars to constrain the parameters of Population III supernovae. We focus on iron peak elements, and, in particular, we try to reproduce the large [Zn/Fe] observed in extremely metal-poor stars. The interesting trends of the observed ratios [Zn, Co, Mn, Cr, V/Fe] can be related to the variation of the relative mass of the complete and incomplete Si-burning regions in supernova ejecta. We find that [Zn/Fe] is larger for deeper mass cuts, smaller neutron excess, and larger explosion energies. The large [Zn/Fe] and [O/Fe] observed in the very metal-poor halo stars suggest deep mixing of complete Si-burning material and a significant amount of fallback in Type II supernovae. Furthermore, large explosion energies (E51 ≳ 2 for M ~ 13 M☉ and E51 ≳ 20 for M ≳ 20 M☉) are required to reproduce [Zn/Fe] ~ 0.5. The observed trends of the abundance ratios among the iron peak elements are better explained with this high-energy ("hypernova") model than with the simple "deep" mass cut effect because the overabundance of Ni can be avoided in the hypernova models. We also present the yields of pair instability supernova explosions of M ≃ 130-300 M☉ stars and discuss that the abundance features of very metal-poor stars cannot be explained by pair instability supernovae.