A Chemical Signature from Fast-rotating Low-metallicity Massive Stars: ROA 276 inωCentauri

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

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 ${M}_{\odot }$, [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.

Citation

Yong, D., Norris, J. E., Da Costa, G. S., Stanford, L. M., Karakas, A. I., Shingles, L. J., …Pignatari, M. (2017). A Chemical Signature from Fast-rotating Low-metallicity Massive Stars: ROA 276 inωCentauri. Astrophysical Journal, 837(2), 176. https://doi.org/10.3847/1538-4357/aa6250

• Journal Article Type: Article
• Online Publication Date: Mar 16, 2017
• Publication Date: Mar 10, 2017
• Deposit Date: May 30, 2023
• Journal: The Astrophysical Journal
• Print ISSN: 0004-637X
• Publisher: American Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 837
• Issue: 2
• Article Number: ARTN 176
• Pages: 176
• DOI: https://doi.org/10.3847/1538-4357/aa6250
• Keywords: Space and Planetary Science; Astronomy and Astrophysics
• Additional Information: Journal title: The Astrophysical Journal; Article type: paper; Article title: A Chemical Signature from Fast-rotating Low-metallicity Massive Stars: ROA 276 inωCentauri; Copyright information: © 2017. The American Astronomical Society. All rights reserved.; Date received: 2016-12-08; Date accepted: 2017-02-17; Online publication date: 2017-03-16