The Hamburg/ESO R-process Enhanced Star survey (HERES) VI. The Galactic Chemical Evolution of Silicon

Details The Hamburg/ESO R-process Enhanced Star survey (HERES) VI. The Galactic Chemical Evolution of Silicon The Hamburg/ESO R-process Enhanced Star survey (HERES) VI. The Galactic Chemical Evolution of Silicon

2010-06-18

arxiv.org/abs/1006.3594v3

Astronomy and Astrophysics

Astrophysics

Solar and Stellar Astrophysics

12 pages, 9 figures, 1 electronical table. Accepted by A & A

Scientific paper

We determined the silicon abundances of 253 metal-poor stars in the metallicity range $-4<\mathrm{[Fe/H]} <-1.5$, based on non-local thermodynamic equilibrium (NLTE) line formation calculations of neutral silicon and high-resolution spectra obtained with VLT-UT2/UVES. The $T_{\mathrm{eff}}$ dependence of [Si/Fe] noticed in previous investigation is diminished in our abundance analysis due to the inclusion of NLTE effects. An increasing slope of [Si/Fe] towards decreasing metallicity is present in our results, in agreement with Galactic chemical evolution models. The small intrinsic scatter of [Si/Fe] in our sample may imply that these stars formed in a region where the yields of type II supernovae were mixed into a large volume, or that the formation of these stars was strongly clustered, even if the ISM was enriched by single SNa II in a small mixing volume. We identified two dwarfs with $\mathrm{[Si/Fe]}\sim +1.0$: HE 0131$-$3953, and HE 1430$-$1123. These main-sequence turnoff stars are also carbon-enhanced. They might have been pre-enriched by sub-luminous supernovae.

Affiliated with

Also associated with

No associations

Rating

The Hamburg/ESO R-process Enhanced Star survey (HERES) VI. The Galactic Chemical Evolution of Silicon 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 The Hamburg/ESO R-process Enhanced Star survey (HERES) VI. The Galactic Chemical Evolution of Silicon, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Hamburg/ESO R-process Enhanced Star survey (HERES) VI. The Galactic Chemical Evolution of Silicon will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-260047