Volume 443, Number 3, December I 2005
|Page(s)||1029 - 1032|
|Published online||15 November 2005|
Sulphur abundances in metal-poor stars
Department of Astronomy and Space Physics, Box 515, 75 120 Uppsala, Sweden e-mail: [korn;ryde]@astro.uu.se
Accepted: 12 September 2005
We investigate the debated “sulphur discrepancy” found among metal-poor stars of the Galactic halo with [Fe/H] < -2. This discrepancy stems in part from the use of two different sets of sulphur lines, the very weak triplet at 8694-95 Å and the stronger triplet lines at 9212-9238 Å. For three representative cases of metal-poor dwarf, turnoff and subgiant stars, we argue that the abundances from the 8694-95 lines have been overestimated which has led to a continually rising trend of [S/Fe] as metallicity decreases. Given that the near-IR region is subject to CCD fringing, these weak lines become excessively difficult to measure accurately in the metallicity regime of [Fe/H] < -2. Based on homogeneously determined spectroscopic stellar parameters, we also present updated [S/Fe] ratios from the 9212-9238 lines which suggest a plateau-like behaviour similar to that seen for other alpha elements.
Key words: stars: abundances / stars: atmospheres / stars: Population II / Galaxy: abundances / Galaxy: evolution / Galaxy: halo
© ESO, 2005
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.