中等贫金属星高分辨率光谱分析Ⅱ.化学元素丰度

High-Resolution Spectral Analysis of the Mildly Metal-Poor Stars Ⅱ.Chemical abundances

在第1篇论文的基础上,确定了样本星的恒星大气参数,得到这些星中9种元素的丰度.讨论了各种元素丰度随[Fe/H]的变化.平均的[Na/Fe]～-0.01dex.接近于太阳丰度.α元素Si和Ca具有几乎相同的丰度模式,而[Ti/Fe]弥散较大,但三者均有随[Fe/H]的减小而增加的趋势.铁峰元素V、Cr、Ni不同丰度处有较大的弥散,[Cr/Fe]在所有样本星中均表现超丰;而[Mn/Fe]却明显过贫,且随金属丰度的增加而增加.

Based on the first paper, here the model parameters of a set of sample stars and the chemical abundances for nine elements are presented. The relations between the elemental abundances and [Fe/H] are also discussed. On average, [Na/Fe] tends to -0.01dex and shows solar pattern. The a elements, Si and Ca, show the same abundance patterns, while [Ti/Fe] has a large scatter. The abundances of these three elements all decrease with [Fe/H] increasing. The iron-peak elements V, Cr, Ni show a large scatter at different metallicity, and [Ca/Fe] is overabundant in all the sample stars, while [Mn/Fe] is definitely underabundant and increases with the metallicity increasing.