Issue |
EAS Publications Series
Volume 24, 2007
CRAL-2006. Chemodynamics: From First Stars to Local Galaxies
|
|
---|---|---|
Page(s) | 269 - 275 | |
DOI | https://doi.org/10.1051/eas:2007036 | |
Published online | 21 April 2007 |
E. Emsellem, H. Wozniak, G. Massacrier, J.-F. Gonzalez, J. Devriendt and N. Champavert (eds)
EAS Publications Series, 24 (2007) 269-275
Chemical and Dynamical Properties of the Stellar Halo
1
Département de Physique, de Génie Physique et d'Optique, Université Laval, Québec, Qc, G1K 7P4, Canada
2
The Observatories of the Carnegie Institution of Washington,
813 Santa Barbara St., Pasadena, CA 91101, USA
3
Centre for Astrophysics, University of Central Lancashire, Preston, PR1 2HE, UK
4
Kavli Institute for Theoretical Physics, Kohn Hall, UC Santa Barbara, Santa Barbara, CA 93106, USA
The difference in density profiles of the contributions from different density peaks to dark matter halos results in certain expectations about the Milky Way's stellar halo. We cut our simulated halo stars into two populations: those forming before/during the last major merger, and those accreted after the last major merger. The former population are more centrally located at z = 0, while stars forming in low mass late forming proto-galaxies are spread through the halo. A difference in observed binding energy distinguishes these two populations. We look at possible chemical abundance signatures of the two populations. We also show that galaxies forming in isolated low σ peaks will form from primordial material. Thus, even though the oldest stars are centrally concentrated as they originated in the early collapsing, densest regions, primordial stars would be found distributed throughout the halo. Thus, the lack of observed metal free stars can be taken as directly constraining the Population III IMF, and the lowest metallicity observed stars can be interpreted as holding clues to the chemical yields of Pop III stars.
© EAS, EDP Sciences, 2007