Metallicities for old stellar systems from Ca II triplet strengths in member giants
Metallicities for old stellar systems from Ca II triplet strengths in member giants
复制标题
来自成员巨星 Ca II 三重态强度的旧恒星系统的金属量
DOI：
10.1086/115769
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发表时间：
1991
期刊：
影响因子：
--
通讯作者：
G. Costa
中科院分区：
文献类型：
--
作者：
T. Armandroff;G. Costa
在六个被充分研究过的银河系球状星团中，大量巨星样本的光谱被用来研究Ca II三重态线强度作为丰度指标的效用。发现最适合丰度分析的图是用V - V HB绘制两条较强三重线的等效宽度之和。该图显示了良好的丰度灵敏度，特别是对于丰度小于约[Fe/H] = -1.2指数的丰度。然而，在较高丰度时，会失去灵敏度，并且由于[Ca/Fe]比值的可能变化而使解释变得复杂。从船底座、Pal 12和船底座矮球状星系的巨星光谱中导出了丰度。
Spectra of a large sample of giants in six well-studied Galactic globular clusters are used to investigate the utility of Ca II triplet line strengths as an abundance indicator. It is found that the most appropriate diagram for abundance analysis is that in which the sum of the equivalent widths of the two stronger triplet lines is plotted against V - V HB . This diagram shows good abundance sensitivity, particulary for abundances less than approximately [Fe/H] = -1.2 dex. At higher abundances, however, there is a loss of sensitivity and the interpretation is complicated by possible changes in the [Ca/Fe] ratio. The abundances from spectra of giants in Eridanus, Pal 12 and Carina dwarf spheroidal galaxy are derived.