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arXiv · 1001.1500

Chemical composition of stellar populations in Omega Centauri

A. F. Marino·G. Piotto·R. Gratton·A. P. Milone·M. Zoccali·L. R. Bedin·S. Villanova·A. Bellini
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Abstract

We derive abundances of Fe, Na, O, and s-elements from GIRAFFE@VLT spectra for more than 200 red giant stars in the Milky Way satellite Omega Centauri. Our preliminary results are that: (i) we confirm that Omega Centauri exibiths large star-to-star metallicity variations ($\sim$ 1.4 dex); (ii) the metallicity distribution reveals the presence of at least five stellar populations with different [Fe/H]; (iii) a clear Na-O anticorrelation is clearly observed for the metal-poor and metal-intermediate populations while apparently the anticorrelation disappears for the most metal-rich populations. Interestingly the Na level grows with iron.

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A. F. Marino, G. Piotto, R. Gratton, A. P. Milone, M. Zoccali, L. R. Bedin, S. Villanova, A. Bellini. 2010-01-10. Chemical composition of stellar populations in Omega Centauri. https://doi.org/10.1017/s1743921310004096

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