Astronomy and Astrophysics – Astrophysics – Galaxy Astrophysics
Scientific paper
2012-01-19
Astronomy and Astrophysics
Astrophysics
Galaxy Astrophysics
to be published in the Proceedings of 3rd Subaru International Conference on Galactic Archeology, at Laforet Shuzenji, Japan,
Scientific paper
We have now completed detailed abundance analyses of more than 100 stars selected as candidate extremely metal-poor stars with [Fe/H] < -3.0 dex. Of these 18 are below -3.3 dex on the scale of the First Stars VLT project led by Cayrel, and 57 are below -3.0 dex on that scale. Ignoring enhancement of carbon which ranges up to very large values, and two C-rich stars with very high N as well, there are 0 to 3 high or low strong outliers for each abundance ratio tested from Mg to Ni. The outliers have been checked and they are real. Ignoring the outliers, the dispersions are in most cases approximately consistent with the uncertainties, except those for [Sr/Fe] and [Ba/Fe], which are much larger. Approximately 6% of the sample are strong outliers in one or more elements between Mg and Ni. This rises to ~15% if minor outliers for these elements and strong outliers for Sr and Ba are included. There are 6 stars with extremely low [Sr/Fe and [Ba/Fe], including one which has lower [Ba/H] than Draco 119, the star found by Fulbright, Rich and Castro to have the lowest such ratio known previously. There is one extreme r-process star.
Christlieb Norbert
Cohen Judith Gamora
McWilliam Andrew
Shectman Stephen
Thompson Ian
No associations
LandOfFree
Outliers in the 0Z Survey 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 Outliers in the 0Z Survey, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Outliers in the 0Z Survey will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-320203