中等贫金属星的元素丰度分析

Abundance Analysis in the Mildly Metal-poor Stars

给出 １１颗中等贫金属星－１．３ ５［Ｆｅ／Ｈ］ ≤－０．６的观测资料，确定了这些样本星的恒星大气参数，得到了这些星中１４种元素的丰度．讨论了各类元素丰度比随金属丰度的变化。α元素（Ｍｇ、 Ｓｉ、 Ｃａ、 Ｔｉ）相对于铁均表现超丰，每一金属丰度处都存在不同程度的弥散．大部分的铁峰元素（Ｖ、Ｃｒ、Ｎｉ、Ｃｕ）也相对于铁超丰，不随［Ｆｅ／Ｈ］而变化，而［Ｍｎ／Ｆｅ］则随金属丰度的增加而增加．［Ｎａ／Ａｌ］在［Ｆｅ／Ｈ］＞－１．１的样本星中表现超车，在［Ｆｅ／Ｈ］＜－１．１的样本中却明显过贫．

We present here some observed data on 11 mildly metal-poor stars with -1.3 ≤ [Fe/H] ≤ -0.6. The model parameters and the abundances of 14 elements are determined. We also discuss the relation between the abundance ratio and the metallicity. The α elements (Mg, Si, Ca, Ti) are overabundant relative to Fe with a varying scatter at each given metallicity. Most of the iron-peak elements (V, Cr, Ni, Cu) are also overabundant relative to Fe by amounts that are independent of [Fe/H], while [Mn/Fe] increases with increasing metallicity. [Na/Al] is overabundant in the sample with [Fe/H] > -1.1 and definitely overdeficient in the sample with [Fe/H]< -1.1.