A LARGE C+N+O ABUNDANCE SPREAD IN GIANT STARS OF THE GLOBULAR CLUSTER NGC 1851
A LARGE C+N+O ABUNDANCE SPREAD IN GIANT STARS OF THE GLOBULAR CLUSTER NGC 1851
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球状星团 NGC 1851 巨星中分布着大量 C N O 丰度
DOI：
10.1088/0004-637x/695/1/l62
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发表时间：
2009
期刊：
影响因子：
--
通讯作者：
J. Norris
中科院分区：
文献类型：
--
作者：
D. Yong;F. Grundahl;F. D’Antona;A. Karakas;J. Lattanzio;J. Norris
测量了四个亮红色巨星的C、N和O的丰度，它们跨越了球状星系团NGC1851中轻元素(Na和Al)和S过程元素(Zr和La)的已知丰度范围。与没有发现明显C+N+O扩散的其他星系团相比，丰度和C+N+O表现出0.6Dex的范围，为4倍。这样的丰度范围为卡西等人提供了支持。两个亚巨型分支种群同龄但具有不同C+N+O丰度混合的情景。此外，Na、Al、Zr和La丰度与C+N+O相关，因此NGC1851星系团是第一个为球状星团轻元素丰度变化提供有力支持的星系团。
Abundances of C, N, and O are determined in four bright red giants that span the known abundance range for light (Na and Al) and s-process (Zr and La) elements in the globular cluster NGC 1851. The abundance sum C+N+O exhibits a range of 0.6 dex, a factor of 4, in contrast to other clusters in which no significant C+N+O spread is found. Such an abundance range offers support for the Cassisi et al. scenario in which the double subgiant branch populations are coeval but with different mixtures of C+N+O abundances. Further, the Na, Al, Zr, and La abundances are correlated with C+N+O, and therefore NGC 1851 is the first cluster to provide strong support for the scenario in which asymptotic giant branch stars are responsible for the globular cluster light element abundance variations.