红团簇巨星的光谱分析及其作为I、K波段标准烛光的研究  

Spectral Analysis of Red Clump Giants and the Research on Using Them as the Standard Candles in Iand K Band

作　　者：刘刚[1] 赵刚[1] 

机构地区：[1]中国科学院国家天文台,北京100012

出　　处：《天文学报》2004年第3期253-265,共13页Acta Astronomica Sinica

基　　金：国家重点基础研究专项基金项目(G1999075406)资助

摘　　要：基于高分辨率、高信噪比光谱观测资料,确定了19颗贫金属红团簇巨星的恒星大气参数,得到样本星4种α族元素(O、Mg、Ca、Si)的化学丰度.讨论了铁丰度与恒星大气参数的相关性以及α族元素丰度随金属丰度的变化.计算了共58颗红团簇巨星在I、K波段的绝对星等,讨论了它们与恒星铁丰度之间的关系.结果表明,在分析铁丰度范围内相对于I波段, K波段的绝对星等与铁丰度的相关性更弱,并且与利用理论模型得到的红团簇巨星I、K波段绝对星等与铁丰度的关系进行了比较与验证.Based on high resolution, high signal-to-noise ratio spectra, we present 19 red clump giants' model parameters, and analyse four α element abundances (O , Mg , Ca , Si) of the sample stars. We discuss the relation between the iron abundances and the stellar atmosphere parameters and show how the α element aoundances change with the increasing metallicity. The absolute magnitudes in I and K bands of 58 red clump giants are computed and the relation between them and the metallicity are also showed. The results indicate that, relative to I band, the absolute magnitudes in K band have the reduced systematic dependence on metallicity. Finally, we compare our results with the theory model.

关 键 词：红团簇 光谱分析 红团簇巨星 恒星 大气 丰度 

分 类 号：P152[天文地球—天文学]