Chemical constraints on the formation of the Galactic thick disk

Summary, in English

We highlight some results from our detailed abundance analysis study of 703 kinematically selected F and G dwarf stars in the solar neighbourhood. The analysis is based on spectra of high-resolution (R = 45 000 to 110 000) and high signal-to-noise (S/N approximate to 150 to 300). The main findings include: (1) at a given metallicity, the thick disk abundance trends are more alpha-enhanced than those of the thin disk; (2) the metal-rich limit of the thick disk reaches at least solar metallicities; (3) the metal-poor limit of the thin disk is around [Fe/H] approximate to -0.8; (4) the thick disk shows an age-metallicity gradient; (5) the thin disk does not show an age-metallicity gradient; (6) the most metal-rich thick disk stars at [Fe/H] approximate to 0 are significantly older than the most metal-poor thin disk stars at [Fe/H] approximate to -0.7; (7) based on our elemental abundances we find that kinematical criteria produce thin and thick disk stellar samples that are biased in the sense that stars from the low-velocity tail of the thick disk are classified as thin disk stars, and stars from the high-velocity tail of the thin disk are classified as thick disk stars; (8) age criteria appears to produce thin and thick disk stellar samples with less contamination.

• Författare: Thomas Bensby; Sofia Feltzing
• Avdelning/ar: Astronomi - Har omorganiserats
• Publiceringsår: 2012
• Språk: Engelska
• Publikation/Tidskrift/Serie: Assembling the Puzzle of the Milky Way
• Volym: 19
• Fulltext: - 1022 kB; Download statistics
• Länkar: http://dx.doi.org/10.1051/epjconf/20121904001
• Dokumenttyp: Konferensbidrag
• Förlag: EDP Sciences
• Ämne: Astronomy, Astrophysics and Cosmology
• Conference name: Conferences of the Assembling the Puzzle of the Milky Way
• Conference date: 2011-04-17 - 2011-04-22
• Conference place: Le Grand-Bornand, France
• Aktiv: Published
• ISBN/ISSN/Övrigt: ISSN: 2101-6275; ISSN: 2100-014X