A chemical signature of first-generation very massive stars
A chemical signature of first-generation very massive stars
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DOI：
10.1126/science.1252633
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发表时间：
2014-08-22
期刊：
影响因子：
56.9
通讯作者：
Lee, Y. S.
中科院分区：
文献类型：
--
作者：
Aoki, W.;Tominaga, N.;Lee, Y. S.
对早期宇宙结构形成的数值模拟预测了几百个太阳质量的恒星的形成。然而，在银河系恒星的化学成分中，还没有发现来自这种超大质量恒星的超新星的明确证据。我们报告的分析非常贫金属星星SDSS J001820.5-093939.2，它具有元素丰度比，显着不同于任何以前已知的星星。这颗星星显示出低的α-元素Fe比率和奇数和偶数元素对之间的巨大反差，例如钪/钛和钴/镍。核合成模型已经预测了质量超过太阳140倍的超新星的这种特征，这表明第一代恒星的质量分布可能会扩展到100个太阳质量或更大。
Numerical simulations of structure formation in the early universe predict the formation of some fraction of stars with several hundred solar masses. No clear evidence of supernovae from such very massive stars has, however, yet been found in the chemical compositions of Milky Way stars. We report on an analysis of a very metal-poor star SDSS J001820.5-093939.2, which possesses elemental-abundance ratios that differ significantly from any previously known star. This star exhibits low [alpha-element Fe] ratios and large contrasts between the abundances of odd and even element pairs, such as scandium/titanium and cobalt/nickel. Such features have been predicted by nucleosynthesis models for supernovae of stars more than 140 times as massive as the Sun, suggesting that the mass distribution of first-generation stars might extend to 100 solar masses or larger.