论文标题
与南部非洲大型望远镜观察到的金属贫困之星
Metal-Poor Stars Observed with the Southern African Large Telescope
论文作者
论文摘要
我们介绍了一项针对南部非洲大型望远镜（盐）观察到的相对明亮（V <13.5）金属贫困星的大规模研究的首次发行，这是基于50颗恒星的高分辨率光谱，其分辨能力为R〜40,000 r〜40,000和S/N〜20，每个像素在4300 Angstrom处。报道了C，SR，BA和EU的元素丰度，以及几种α-元素（MG，CA，SC，TI，TI，V）和铁峰元素（MN，CO，NI，ZN）。我们发现了各种各样的丰度模式，其中包括与碳增强金属贫困CEMP-I和CEMP-R星的特征一致的。我们发现，50个（30％）中有15个增强了碳（具有[C/Fe]>+ 0.70），并且在R-Process元素中，在R-Process增强的恒星中，大量的（50％，52％中的26％）得到了增强，5个是R-ii（[Eu/Fe]> 1.0> 1.0）（21个新的），而R-ii强烈增强了R-ii（eu/fe+ 1.0），并且是新的21架。 （+0.3 <= [eu/fe] <=+ 1..0）星星。在我们的样品中有八颗星，根据它们的丰度和运动学，是金属螺旋厚的烟道种群的可能成员。我们还将测量的丰度与祖细胞增强模型进行了比较，并发现我们大多数恒星的丰度模式可以归因于一个（而不是多个）富集事件。
We present the first release of a large-scale study of relatively bright (V < 13.5) metal-poor stars observed with the Southern African Large Telescope (SALT), based on high-resolution spectra of 50 stars with a resolving power of R ~ 40,000 and S/N ~ 20 per pixel at 4300 Angstrom. The elemental abundances of C, Sr, Ba, and Eu are reported, as well as several alpha-elements (Mg, Ca, Sc, Ti, V) and iron-peak elements (Mn, Co, Ni, Zn). We find a diverse array of abundance patterns, including several consistent with the signatures of carbon-enhanced metal-poor CEMP-i and CEMP-r stars. We find that 15 of 50 (30%) are carbon enhanced (with [C/Fe] >+ 0.70), and that a large fraction (26 of 50, 52%) are enhanced in r-process elements, among the r-process-enhanced stars, five are strongly enhanced r-II ([Eu/Fe] >+ 1.0) stars (two of which are newly discovered) and 21 are newly discovered moderately enhanced r-I (+0.3 <= [Eu/Fe] <=+ 1..0) stars. There are eight stars in our sample that, on the basis of their abundances and kinematics, are possible members of the metal-weak thick-disk population. We also compare our measured abundances to progenitor-enrichment models, and find that the abundance patterns for the majority of our stars can be attributed to a single (rather than multiple) enrichment event.
