First Stars XIV. Sulfur abundances in extremely metal-poor (EMP) stars

Details First Stars XIV. Sulfur abundances in extremely metal-poor (EMP) stars First Stars XIV. Sulfur abundances in extremely metal-poor (EMP) stars

2010-12-20

arxiv.org/abs/1012.4358v2

Astronomy and Astrophysics

Astrophysics

Solar and Stellar Astrophysics

10 pages, accepted for publication in A&A

Scientific paper

Sulfur is important: the site of its formation is uncertain, and at very low metallicity the trend of [S/Fe] against [Fe/H] is controversial. Below [Fe/H]=-2.0, [S/Fe] remains constant or it decreases with [Fe/H], depending on the author and the multiplet used in the analysis. Moreover, although sulfur is not significantly bound in dust grains in the ISM, it seems to behave differently in DLAs and in old metal-poor stars. We aim to determine precise S abundance in a sample of extremely metal-poor stars taking into account NLTE and 3D effects. NLTE profiles of the lines of the multiplet 1 of SI have been computed using a new model atom for S. We find sulfur in EMP stars to behave like the other alpha-elements, with [S/Fe] remaining approximately constant for [Fe/H]<-3. However, [S/Mg] seems to decrease slightly as a function of [Mg/H]. The overall abundance patterns of O, Na, Mg, Al, S, and K are best matched by the SN model yields by Heger & Woosley. The [S/Zn] ratio in EMP stars is solar, as found also in DLAs. We obtain an upper limit on the abundance of sulfur, [S/Fe] < +0.5, for the ultra metal-poor star CS 22949-037. This, along with a previous reported measurement of zinc, argues against the conjecture that the light-element abundances pattern in this star, and, by analogy, the hyper metal-poor stars HE 0107-5240 and HE 1327-2326, are due to dust depletion.

Affiliated with

Also associated with

No associations

Rating

First Stars XIV. Sulfur abundances in extremely metal-poor (EMP) stars does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with First Stars XIV. Sulfur abundances in extremely metal-poor (EMP) stars, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and First Stars XIV. Sulfur abundances in extremely metal-poor (EMP) stars will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-454362