Thomas Bensby
Senior lecturer
The Gaia-ESO Survey: alpha-abundances of metal-poor stars
Author
Summary, in English
We performed a detailed study of the ratio of low-alpha to high-alpha stars in the Galactic halo as observed by the Gaia-ESO Survey. Using a sample of 381 metal-poor stars from the second internal data release, we found that the value of this ratio did not show evidence of systematic trends as a function of metallicity, surface gravity, Galactic latitude, Galactic longitude, height above the Galactic plane, and Galactocentric radius. We conclude that the alpha(poor)/alpha(rich) value of 0.28 +/- 0.08 suggests that in the inner halo, the larger portion of stars were formed in a high star formation rate environment, and about 15% of the metal-poor stars originated from much lower star formation rate environments.
Department/s
- Lund Observatory - Has been reorganised
Publishing year
2014
Language
English
Publication/Series
Astronomy & Astrophysics
Volume
571
Document type
Journal article
Publisher
EDP Sciences
Topic
- Astronomy, Astrophysics and Cosmology
Keywords
- stars: abundances
- Galaxy: halo
Status
Published
Project
- Gaia-ESO Survey
ISBN/ISSN/Other
- ISSN: 0004-6361