DOI:
10.1051/0004-6361/201425099
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
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.
URL:
https://ui.adsabs.harvard.edu/#abs/2014A&A...571L...5J/abstract
Keywords:
Galaxy: halo; Stars: abundances