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arXiv · 0808.3723

Stellar Evolution in the Early Universe

R. Hirschi·U. Frischknecht·F. -K. Thielemann·M. Pignatari·C. Chiappini·S. Ekstroem·G. Meynet·A. Maeder
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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 $Z$. 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.

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R. Hirschi, U. Frischknecht, F. -K. Thielemann, M. Pignatari, C. Chiappini, S. Ekstroem, G. Meynet, A. Maeder. 2008-08-27. Stellar Evolution in the Early Universe. https://doi.org/10.1017/s1743921308024976

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