Chemical Abundances of Luminous Cool Stars in the Galactic Center from High-Resolution Infrared Spectroscopy
Chemical Abundances of Luminous Cool Stars in the Galactic Center from High-Resolution Infrared Spectroscopy
复制标题
高分辨率红外光谱显示银河系中心发光冷星的化学丰度
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
D. Terndrup
中科院分区：
文献类型：
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作者：
Katia Cunha;K. Sellgren;V. Smith;Solange V. Ramírez;Robert D. Blum;D. Terndrup
我们目前的化学丰度在一个样本的发光冷恒星位于30 pc的银河系中心。碳、氮、氧、钙和铁的丰度来自H和K波段的高分辨率红外光谱。丰度的结果表明，[O/Fe]和[Ca/Fe]的增加，分别为+0.2和+0.3德克斯，相对于太阳或银河系盘在近太阳的铁丰度。银河系中心的恒星显示出几乎均匀的铁丰度，接近太阳。平均值A（Fe）= 7.59 ± 0.06，与前人工作一致。银河系中心恒星之间的铁丰度的总范围，0.16德克斯，是显着窄于文献中发现的老鼓人口的铁丰度分布。我们对银河系中心30秒差距内当今铁丰度的快照对年龄小于1 Gyr的恒星进行了采样;时间（或空间）上更大的样本可能会发现丰度分布更广。
We present chemical abundances in a sample of luminous cool stars located within 30 pc of the Galactic center. Abundances of carbon, nitrogen, oxygen, calcium, and iron were derived from high-resolution infrared spectra in the H and K bands. The abundance results indicate that both [O/Fe] and [Ca/Fe] are enhanced, respectively, by averages of +0.2 and +0.3 dex, relative to either the Sun or the Milky Way disk at near-solar Fe abundances. The Galactic center stars show a nearly uniform and nearly solar iron abundance. The mean value of A(Fe) = 7.59 ± 0.06 agrees well with previous work. The total range in Fe abundance among Galactic center stars, 0.16 dex, is significantly narrower than the iron abundance distributions found in the literature for the older bulge population. Our snapshot of the current-day Fe abundance within 30 pc of the Galactic center samples stars with an age less than 1 Gyr; a larger sample in time (or space) may find a wider spread in abundances.