The helium abundances of ω Centauri

被引：213

作者：

Norris, JE ^{[1
]}

机构：

[1] Australian Natl Univ, Mt Stromlo Observ, Res Sch Astron & Astrophys, Weston, ACT 2611, Australia

来源：

ASTROPHYSICAL JOURNAL | 2004年 / 612卷 / 01期

关键词：

globular clusters : individual (omega Centauri); stars : abundances; stars : evolution; stars : Population II;

D O I：

10.1086/423986

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

Recent Hubble Space Telescope color magnitude diagrams (CMDs) of omega Centauri, which clearly show three sequences in the region of the main-sequence turnoff together with a double lower main sequence, are explained in terms of three populations having canonical heavy-element abundances ([Fe/H]=-1.7, -1.2, and -0.6), reasonable proportions and ages, but with surprising helium abundances. In particular, the CMD morphology of the second population ([Fe/H]=-1.2) is very well represented with a helium abundance much larger, by DeltaYsimilar to0.12, than that of the first ([Fe/H]=-1.7), which may hold the key to an understanding of the double lower main sequence.

引用

页码：L25 / L28

页数：4

共 39 条

[1]

Anderson J, 2003, ASTR SOC P, V296, P125

[2]

ANDERSON J, 1997, THESIS UC BERKELEY

[3]

ANDERSON J, 2002, ASP C SER, V265, P87

[4] ω Centauri:: The population puzzle goes deeper [J].