Hansen, TT;
Simon, JD;
Marshall, JL;
Li, TS;
Carollo, D;
DePoy, DL;
Nagasawa, DQ;
... Walker, AR; + view all
(2017)
An r-process Enhanced Star in the Dwarf Galaxy Tucana III.
Astrophysical Journal
, 838
(1)
10.3847/1538-4357/aa634a.
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Abstract
Chemically peculiar stars in dwarf galaxies provide a window for exploring the birth environment of stars with varying chemical enrichment. We present a chemical abundance analysis of the brightest star in the newly discovered ultra-faint dwarf galaxy candidate Tucana III. Because it is particularly bright for a star in an ultra-faint Milky Way (MW) satellite, we are able to measure the abundance of 28 elements, including 13 neutron-capture species. This star, DES J235532.66−593114.9 (DES J235532), shows a mild enhancement in neutron-capture elements associated with the r-process and can be classified as an r-I star. DES J235532 is the first r-I star to be discovered in an ultra-faint satellite, and Tuc III is the second extremely low-luminosity system found to contain r-process enriched material, after Reticulum II. Comparison of the abundance pattern of DES J235532 with r-I and r-II stars found in other dwarf galaxies and in the MW halo suggests a common astrophysical origin for the neutron-capture elements seen in all r-process enhanced stars. We explore both internal and external scenarios for the r-process enrichment of Tuc III and show that with abundance patterns for additional stars, it should be possible to distinguish between them.
| Type: | Article |
|---|---|
| Title: | An r-process Enhanced Star in the Dwarf Galaxy Tucana III |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.3847/1538-4357/aa634a |
| Publisher version: | http://dx.doi.org/10.3847/1538-4357/aa634a |
| Language: | English |
| Additional information: | © 2017. The American Astronomical Society. All rights reserved |
| Keywords: | Science & Technology, Physical Sciences, Astronomy & Astrophysics, Galaxies: Abundances, Galaxies: Dwarf, Stars: Abundances, Stars: Chemically Peculiar, Metal-Poor Stars, Horizontal-Branch Stars, Dark Energy Survey, Red Giant Branch, Spheroidal Galaxy, Chemical Evolution, Process Nucleosynthesis, Spectroscopic Analysis, Detailed Abundances, Globular-Clusters |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery.ucl.ac.uk/id/eprint/1556158 |
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