MIXED POPULATIONS IN GLOBULAR CLUSTERS: ET TU, 47 TUC?

被引：120

作者：

Anderson, J. ^{[1
]}

Piotto, G. ^{[2
]}

King, I. R. ^{[3
]}

Bedin, L. R. ^{[1
]}

Guhathakurta, P. ^{[4
]}

机构：

[1] Space Telescope Sci Inst, Baltimore, MD 21218 USA

[2] Univ Padua, Dept Astron, I-35122 Pd, Italy

[3] Univ Washington, Dept Astron, Seattle, WA 98195 USA

[4] Univ Calif Santa Cruz, Lick Observ, Santa Cruz, CA 95064 USA

来源：

ASTROPHYSICAL JOURNAL LETTERS | 2009年 / 697卷 / 01期

关键词：

globular clusters: individual (NGC 104); Hertzsprung-Russell (HR) diagram; DOUBLE SUBGIANT BRANCH; OMEGA-CENTAURI; MAIN-SEQUENCE; ISOCHRONES; ABUNDANCE; NGC-1851;

D O I：

10.1088/0004-637X/697/1/L58

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We exploit the large number of archival Hubble Space Telescope images of 47 Tuc to examine its subgiant branch (SGB) and main sequence (MS) for signs of multiple populations. In the cluster core, we find that the cluster's SGB exhibits a clear spread in luminosity, with at least two distinct components: a brighter one with a spread that is real but not bimodal, and a second one about 0.05 mag fainter, containing about 10% of the stars. In a less crowded field 6' from the center, we find that the MS is broadened much more than can be accounted for by photometric errors, and that this broadening increases at fainter magnitudes.

引用

页码：L58 / L62

页数：5

共 16 条

[1]

Anderson J., 2006, 200601 ACS ISR

[2] Transforming observational data and theoretical isochrones into the ACS/WFC Vega-mag system [J].