Mg abundances in metal-poor halo stars as a tracer of early Galactic mixing

Details Mg abundances in metal-poor halo stars as a tracer of early Galactic mixing Mg abundances in metal-poor halo stars as a tracer of early Galactic mixing

2004-10-07

arxiv.org/abs/astro-ph/0410180v1

Astronomy and Astrophysics

Astrophysics

Astronomy&Astrophysics accepted September 27th, 2004 18 pages, 6 figures

Scientific paper

10.1051/0004-6361:20041034

We present results of a detailed chemical analysis performed on 23 main-sequence turnoff stars having -3.4<=[Fe/H]<=-2.2, a sample selected to be highly homogeneous in T_eff and log(g). We investigate the efficiency of mixing in the early Galaxy by means of the [Mg/Fe] ratio, and find that all values lie within a total range of 0.2 dex, with a standard deviation about the mean of 0.06 dex, consistent with measurement errors. This implies there is "little or no intrinsic scatter" in the early ISM, as suggested also by the most recent results from high-quality VLT observations. These results are in contrast with inhomogeneous Galactic chemical evolution (iGCE) models adopting present supernova (SN) II yields, which predict a peak-to-peak scatter in [Mg/Fe] as high as 1 dex at very low metallicity, with a corresponding standard deviation of about 0.4 dex. We propose that cooling and mixing timescales should be investigated in iGCE models to account for the apparent disagreement with present observations. The contrast between the constancy and small dispersion of [Mg/Fe] reported here and the quite different behaviour of [Ba/Fe] indicates, according to this interpretation, that Mg and Ba are predominantly synthesised in different progenitor mass ranges.

Affiliated with

Also associated with

No associations

Rating

Mg abundances in metal-poor halo stars as a tracer of early Galactic mixing 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 Mg abundances in metal-poor halo stars as a tracer of early Galactic mixing, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Mg abundances in metal-poor halo stars as a tracer of early Galactic mixing will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-215798