Spectroscopic Studies of Extremely Metal-poor Stars with the Subaru High-Dispersion Spectrograph. IV. The α-Element-Enhanced Metal-poor Star BS 16934–002
Spectroscopic Studies of Extremely Metal-poor Stars with the Subaru High-Dispersion Spectrograph. IV. The α-Element-Enhanced Metal-poor Star BS 16934–002
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DOI：
10.1086/512601
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发表时间：
2007-01
期刊：
影响因子：
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通讯作者：
W. Aoki;S. Honda;T. Beers;M. Takada-Hidai;Nobuyuki Iwamoto;Nozomu Tominaga;H. Umeda;Ken’ichi Nomoto;J. Norris;Sean G. Ryan
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文献类型：
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作者：
W. Aoki;S. Honda;T. Beers;M. Takada-Hidai;Nobuyuki Iwamoto;Nozomu Tominaga;H. Umeda;Ken’ichi Nomoto;J. Norris;Sean G. Ryan
对极贫金属的（[Fe/H] = -2.7）星星BS 16934-002，它在我们以前的工作中被鉴定为Mg和Sc的高丰度星星。以及BS 16934-002的Sc。特别令人感兴趣的是，在这个天体中没有发现过量的C或N，而CS 22949-037和CS 29498-043是两颗先前已知的富碳、极度贫金属、α元素过量的恒星。没有建立的核合成模型可以解释观察到的BS 16934-002丰度模式。一个超新星模型，包括混合和回落，并假设爆炸前严重的质量损失，讨论作为BS 16934-002的候选祖先。
A detailed elemental abundance analysis has been carried out for the very metal-poor ([Fe/H] = -2.7) star BS 16934-002, which was identified in our previous work as a star exhibiting large overabundances of Mg and Sc. A comparison of the abundance pattern of this star with that of the well-studied metal-poor star HD 122563 indicates excesses of O, Na, Mg, Al, and Sc in BS 16934-002. Of particular interest, no excess of C or N is found in this object, in contrast to CS 22949-037 and CS 29498-043, two previously known carbon-rich, extremely metal-poor stars with excesses of the α-elements. No established nucleosynthesis model exists that explains the observed abundance pattern of BS 16934-002. A supernova model, including mixing and fallback and assuming severe mass loss before explosion, is discussed as a candidate progenitor of BS 16934-002.