The Gaia-ESO Survey: the most metal-poor stars in the Galactic bulge
2014 (English)In: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 445, no 4, 4241-4246 p.Article in journal (Refereed) Published
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.
Place, publisher, year, edition, pages
2014. Vol. 445, no 4, 4241-4246 p.
stars: abundances, stars: Population II, Galaxy: bulge, Galaxy: evolution
IdentifiersURN: urn:nbn:se:uu:diva-242390DOI: 10.1093/mnras/stu1991ISI: 000346963300071OAI: oai:DiVA.org:uu-242390DiVA: diva2:783492