The Gaia-ESO Survey: α-abundances of metal-poor stars

DOI: 
10.1051/0004-6361/201425099
Publication date: 
01/11/2014
Main author: 
Jackson-Jones R.
IAA authors: 
Costado M.T.
Authors: 
Jackson-Jones R., Jofré P., Hawkins K., Hourihane A., Gilmore G., Kordopatis G., Worley C., Randich S., Vallenari A., Bensby T., Bragaglia A., Flaccomio E., Korn A.J., Recio-Blanco A., Smiljanic R., Costado M.T., Heiter U., Hill V., Lardo C., De Laverny P., Guiglion G., Mikolaitis S., Zaggia S., Tautvaišiene G.
Journal: 
Astronomy and Astrophysics
Publication type: 
Article
Volume: 
571
Pages: 
Number: 
L5
Abstract: 
We performed a detailed study of the ratio of low-α to high-α 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 αpoor/αrich 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. © 2014 ESO.
Database: 
WOK
SCOPUS
ADS
URL: 
https://ui.adsabs.harvard.edu/#abs/2014A&A...571L...5J/abstract
ADS Bibcode: 
2014A&A...571L...5J
Keywords: 
Galaxy: halo; Stars: abundances