Stellar Evolution in the Early Universe
Abstract
Massive stars played a key role in the early evolution of the Universe. They formed with the first halos and started the re-ionisation. It is therefore very important to understand their evolution. In this paper, we describe the strong impact of rotation induced mixing and mass loss at very low . The strong mixing leads to a significant production of primary nitrogen 14, carbon 13 and neon 22. Mass loss during the red supergiant stage allows the production of Wolf-Rayet stars, type Ib,c supernovae and possibly gamma-ray bursts (GRBs) down to almost Z=0 for stars more massive than 60 solar masses. Galactic chemical evolution models calculated with models of rotating stars better reproduce the early evolution of N/O, C/O and C12/C13. We calculated the weak s-process production induced by the primary neon 22 and obtain overproduction factors (relative to the initial composition, Z=1.e-6) between 100-1000 in the mass range 60-90.
Cite
@article{arxiv.0808.3723,
title = {Stellar Evolution in the Early Universe},
author = {R. Hirschi and U. Frischknecht and F. -K. Thielemann and M. Pignatari and C. Chiappini and S. Ekstroem and G. Meynet and A. Maeder},
journal= {arXiv preprint arXiv:0808.3723},
year = {2009}
}
Comments
8 pages, 4 figures, proceedings of IAU Symposium 255, "Low-Metallicity Star Formation: From the First stars to Dwarf Galaxies", L.K. Hunt, S. Madden & R. Schneider, eds