The Gaia-ESO Survey: the most metal-poor stars in the Galactic bulge
Keywords: stars: population ii, stars: abundances, galaxy: bulge, galaxy: evolution
Abstract
We present the first results of the EMBLA survey (Extremely Metal-poor BuLge stars with AAOmega), aimed at finding metal-poor stars in the Milky Way bulge, where the oldest stars should now preferentially reside. EMBLA utilizes SkyMapper photometry to pre-select metal-poor candidates, which are subsequently confirmed using AAOmega spectroscopy. We describe the discovery and analysis of four bulge giants with -2.72 <= [Fe/H] <= -2.48, the lowest metallicity bulge stars studied with high-resolution spectroscopy to date. Using FLAMES/UVES spectra through the Gaia-ESO Survey we have derived abundances of twelve elements. Given the uncertainties, we find a chemical similarity between these bulge stars and halo stars of the same metallicity, although the abundance scatter may be larger, with some of the stars showing unusual [alpha/Fe] ratios.
Más información
Título según WOS: | The Gaia-ESO Survey: the most metal-poor stars in the Galactic bulge |
Título según SCOPUS: | The Gaia-ESO Survey: The most metal-poor stars in the Galactic bulge |
Título de la Revista: | MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY |
Volumen: | 445 |
Número: | 4 |
Editorial: | OXFORD UNIV PRESS |
Fecha de publicación: | 2014 |
Página de inicio: | 4241 |
Página final: | 4246 |
Idioma: | English |
DOI: |
10.1093/mnras/stu1991 |
Notas: | ISI, SCOPUS |