A Differential Study of the Oxygen Abundances in the Galactic Thin and Thick Disks
Bensby, Thomas; Feltzing, Sofia; Lundström, Ingemar (2004). A Differential Study of the Oxygen Abundances in the Galactic Thin and Thick Disks Carnegie Observatories Astrophysics Series, Origin and Evolution of the Elements, 4,: Carnegie Observatories
Conference Proceeding/Paper
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Published
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English
Authors:
Bensby, Thomas
;
Feltzing, Sofia
;
Lundström, Ingemar
Department:
Lund Observatory - Has been reorganised
Abstract:
First results from a study into the abundance trends of oxygen in the Galactic thin and thick disks are presented. Oxygen abundances for 63nearby F and G dwarf stars, based on very high resolution spectra (R∼215 000) and high signal-to-noise (S/N>400) of the faint forbidden oxygen line at 6300Å, have been determined. Our findings can be summarized as follows: 1) at [Fe/H]<0 the oxygen trends in thethin and thick disk are smooth and distinct, indicating their different origins, 2) [O/Fe] for the thick disk stars show a turn-over at[Fe/H]∼-0.35, indicating the peak of the enrichment from SNe type Ia to the interstellar medium, 3) the thin disk stars show a shallow decrease going from [Fe/H] ∼-0.7 to the highest metallicities with no apparent turn-over present indicating a more quiet star formation history, and 4) [O/Fe] continues to decrease at [Fe/H] > 0 without showing the leveling out that previously has been seen.
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