期刊
ASTROPHYSICAL JOURNAL LETTERS
卷 707, 期 2, 页码 L190-L194出版社
IOP PUBLISHING LTD
DOI: 10.1088/0004-637X/707/2/L190
关键词
globular clusters: individual (NGC 1851); stars: abundances; stars: evolution; stars: horizontal-branch
资金
- Korean Ministry of Education, Science Technology
- KOSEF
- KOSEF/MEST [2009-0080851]
- ARCSEC
- AURA through the NSF under AURA Cooperative Agreement [AST 0132798]
- National Research Foundation of Korea [2009-0080851, 2006-0051702, 과06A1403] Funding Source: Korea Institute of Science & Technology Information (KISTI), National Science & Technology Information Service (NTIS)
There is a growing body of evidence for the presence of multiple stellar populations in some globular clusters, including NGC 1851. For most of these peculiar globular clusters, however, the evidence for the multiple red giant branches (RGBs) having different heavy elemental abundances as observed in omega Centauri is hitherto lacking, although spreads in some lighter elements are reported. It is therefore not clear whether they also share the suggested dwarf galaxy origin of omega Cen or not. Here we show from the CTIO 4 m UVI photometry of the globular cluster NGC 1851 that its RGB is clearly split into two in the U - I color. The two distinct RGB populations are also clearly separated in the abundance of heavy elements as traced by calcium, suggesting that the Type II supernovae enrichment is also responsible, in addition to the pollutions of lighter elements by intermediate-mass asymptotic giant branch stars or fast-rotating massive stars. The RGB split, however, is not shown in the V - I color, as indicated by previous observations. Our stellar population models show that this and the presence of bimodal horizontal-branch distribution in NGC 1851 can be naturally reproduced if the metal-rich second generation stars are also enhanced in helium.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据