Four-hundred Very Metal-poor Stars Studied with LAMOST and Subaru. II. Elemental Abundances
Four-hundred Very Metal-poor Stars Studied with LAMOST and Subaru. II. Elemental Abundances
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DOI：
10.3847/1538-4357/ac6514
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发表时间：
2022-06-01
影响因子：
4.9
通讯作者：
Zhao, Gang
中科院分区：
文献类型：
--
作者：
Li, Haining;Aoki, Wako;Zhao, Gang
我们提出了均匀的丰度超过20种元素的385个非常贫金属（VMP）星的基础上LAMOST调查和后续观测与斯巴鲁望远镜。它是由单一项目研究的最大的高分辨率VMP样本（包括363个新物体），也是第一次尝试根据盖亚星系精确确定如此大样本的进化阶段。样品覆盖了从[Fe/H]小于或接近-1.7到[Fe/H]接近-4.3的广泛金属丰度范围，包括超过110个[Fe/H] 0.7的天体，对于关闭星，取决于对未确定C丰度的天体的处理，C丰度在20%-30%的范围内，远高于巨星的C丰度（接近8%）。已经确认了12颗贫镁星（[Mg/Fe] < 0.0），其金属丰度范围从[Fe/H]到-3.8到-1.7不等。在-3.4 < [Fe/H] <-2.0的范围内发现了12颗富Eu星（[Eu/Fe] > 1.0），扩大了r过程增强星的样本。
We present homogeneous abundance analysis of over 20 elements for 385 very metal-poor (VMP) stars based on the LAMOST survey and follow-up observations with the Subaru Telescope. It is the largest high-resolution VMP sample (including 363 new objects) studied by a single program, and the first attempt to accurately determine evolutionary stages for such a large sample based on Gaia parallaxes. The sample covers a wide metallicity range from [Fe/H] less than or similar to -1.7 down to [Fe/H] similar to -4.3, including over 110 objects with [Fe/H] 0.7) is in the range of 20%-30% for turnoff stars depending on the treatment of objects for which C abundance is not determined, which is much higher than that in giants (similar to 8%). Twelve Mg-poor stars ([Mg/Fe] < 0.0) have been identified in a wide metallicity range from [Fe/H] similar to -3.8 through -1.7. Twelve Eu-rich stars ([Eu/Fe] > 1.0) have been discovered in -3.4 < [Fe/H] < -2.0, enlarging the sample of r-process-enhanced stars with relatively high metallicity.