A Chemical Signature from Fast-rotating Low-metallicity Massive Stars: ROA 276 in ω Centauri*

2017/02/23 by David Yong, John E. Norris, Gary S. Da Costa +8
Physics and Astronomy · #Astro and Planetary Science #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Metallicity #Physics #Signature (topology) #Stars #Stellar, planetary, and galactic studies #astro-ph.GA #astro-ph.SR

paper · pdf · doi:10.3847/1538-4357/aa6250

ApJ in press

arxiv created 2017/02/23 · openalex publication_date 2017/03/10 · arxiv updated 2017/03/22 · openalex created_date 2017/03/23 · openalex updated_date 2026/08/05

Abstract

Abstract We present a chemical abundance analysis of a metal-poor star, ROA 276, in the stellar system ω 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 ω Cen star ROA 46, is best fit by a fast-rotating low-metallicity massive stellar model of 20 , [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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