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arXiv · 1702.07087

A chemical signature from fast-rotating low-metallicity massive stars: ROA 276 in omega Centauri

David Yong·John E. Norris·Gary S. Da Costa·Laura M. Stanford·Amanda I. Karakas·Luke J. Shingles·Raphael Hirschi·Marco Pignatari
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Abstract

We present a chemical abundance analysis of a metal-poor star, ROA 276, in the stellar system omega Centauri. We confirm that this star has an unusually high [Sr/Ba] abundance ratio. Additionally, ROA 276 exhibits remarkably high abundance ratios, [X/Fe], for all elements from Cu to Mo along with normal abundance ratios for the elements from Ba to Pb. The chemical abundance pattern of ROA 276, relative to a primordial omega Cen star ROA 46, is best fit by a fast-rotating low-metallicity massive stellar model of 20 Msun, [Fe/H] = -1.8, and an initial rotation 0.4 times the critical value; no other nucleosynthetic source can match the neutron-capture element distribution. ROA 276 arguably offers the most definitive proof to date that fast-rotating massive stars contributed to the production of heavy elements in the early Universe.

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David Yong, John E. Norris, Gary S. Da Costa, Laura M. Stanford, Amanda I. Karakas, Luke J. Shingles, Raphael Hirschi, Marco Pignatari. 2017-02-23. A chemical signature from fast-rotating low-metallicity massive stars: ROA 276 in omega Centauri. https://doi.org/10.3847/1538-4357%2Faa6250

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