2003/04/10 by T. Bensby, Bensby, T., S. Feltzing +3
Physics and Astronomy · #Astrophysics (astro-ph) #FOS: Physical sciences #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0304182
5 pages, Carnegie Observatories Astrophysics Series, Vol. 4: Origin and Evolution of the Elements, ed. A. McWilliam and M. Rauch (Pasadena: Carnegie Observatories, http://www.ociw.edu/ociw/symposia/series/symposium4/proceedings.html)
arxiv created 2010/04/27 · arxiv updated 2010/04/28
First results from a study into the abundance trends of oxygen in the Galactic thin and thick disks are presented. Oxygen abundances for 63 nearby 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 6300 Å, have been determined. Our findings can be summarized as follows: \bf 1) at \rm [Fe/H]<0 the oxygen trends in the thin and thick disk are smooth and distinct, indicating their different origins, \bf 2) \rm [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, \bf 3) the thin disk stars show a shallow decrease going from \rm [Fe/H] ∼ -0.7 to the highest metallicities with no apparent turn-over present indicating a more quiet star formation history, and \bf 4) \rm [O/Fe] continues to decrease at \rm [Fe/H]>0 without showing the leveling out that previously has been seen.