The explosion energy of early stellar populations: the Fe-peak element ratios in low-metallicity damped Lyα systems
The explosion energy of early stellar populations: the Fe-peak element ratios in low-metallicity damped Lyα systems
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DOI：
10.1093/mnras/stt282
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发表时间：
2012-11
影响因子：
4.8
通讯作者：
R. Cooke;M. Pettini;R. Jorgenson;M. Murphy;G. Rudie;Charles C. Steidel University of California;Santa Cruz;I. O. Astronomy;U. Cambridge;Institute for Astronomy;U. Hawaii;S. U. Technology;C. I. O. Technology.
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文献类型：
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作者：
R. Cooke;M. Pettini;R. Jorgenson;M. Murphy;G. Rudie;Charles C. Steidel University of California;Santa Cruz;I. O. Astronomy;U. Cambridge;Institute for Astronomy;U. Hawaii;S. U. Technology;C. I. O. Technology.
最低金属丰度的铁峰元素(钛锌)的相对丰度与核坍缩超新星爆炸的物理机制密切相关。以25个极贫金属阻尼型Lyα系统(DLAS)为例，研究了铁峰元素比随金属度的变化趋势。对于25个DLA中的9个，可以从检测到的吸收线确定一个或多个钛、铬、钴、镍、锌/铁丰度比的直接测量(或有用的上限)。对于剩下的系统(没有检测到)，我们设计了一种新的光谱堆积形式来估计在这个金属丰度区域内DLA布居的典型的Fe峰元素比率。我们将这些数据与银晕贫金属恒星的类似测量结果进行了比较，并与无金属恒星中爆炸性核合成的详细计算进行了比较。我们得出的结论是，我们样本中的大部分DLA都是由恒星作为核心塌缩超新星爆炸时释放出1.2x10^(51)erg的能量而丰富的。最后，我们讨论了当30m级望远镜出现时，用太阳的1/1000的Fe/H测量DLA中的Fe峰元素比率的令人兴奋的前景。只有到那时，我们才能确定第一批恒星的超新星释放的能量。
The relative abundances of the Fe-peak elements (Ti–Zn) at the lowest metallicities are intimately linked to the physics of core-collapse supernova explosions. With a sample of 25 very metal poor damped Lyα systems (DLAs), we investigate the trends of the Fe-peak element ratios with metallicity. For nine of the 25 DLAs, a direct measurement (or useful upper limit) of one or more of the Ti, Cr, Co, Ni, Zn/Fe abundance ratios could be determined from detected absorption lines. For the remaining systems (without detections), we devised a new form of spectral stacking to estimate the typical Fe-peak element ratios of the DLA population in this metallicity regime. We compare these data to analogous measurements in metal-poor stars of the Galactic halo and to detailed calculations of explosive nucleosynthesis in metal-free stars. We conclude that most of the DLAs in our sample were enriched by stars that released an energy of ≲1.2 × 10^(51) erg when they exploded as core-collapse supernovae. Finally, we discuss the exciting prospect of measuring Fe-peak element ratios in DLAs with Fe/H < 1/1000 of solar when 30-m class telescopes become available. Only then will we be able to pin down the energy that was released by the supernovae of the first stars.