A Large C+n+o Abundance Spread in Giant Stars of the Globular

Abstract

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. (2008) 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 AGB stars are responsible for the globular cluster light element abundance variations. Subject headings: Galaxy: Globular Clusters: Individual: NGC 1851, Galaxy: Abundances, Stars: Abundances

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Cite this paper

@inproceedings{DANTONA2009ALC, title={A Large C+n+o Abundance Spread in Giant Stars of the Globular}, author={FRANCESCA D’ANTONA and AMANDA I. KARAKAS and JOHN C. LATTANZIO and JOHN E. NORRIS}, year={2009} }