Stellar Evolution at Low Metallicity

Hirschi, R.; Chiappini, C.; Meynet, G.; Maeder, A.; Ekstrom, S.

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 review, we first recall the effect of metallicity (Z) on the evolution of massive stars. We then 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. Finally, the impact of magnetic fields is discussed in the context of GRBs.

Citation

Hirschi, R., Chiappini, C., Meynet, G., Maeder, A., & Ekstrom, S. Stellar Evolution at Low Metallicity. Presented at Massive Stars as Cosmic Engines

• Presentation Conference Type: Conference Paper (published)
• Conference Name: Massive Stars as Cosmic Engines
• Online Publication Date: Dec 1, 2007
• Publication Date: Dec 1, 2007
• Deposit Date: Jul 7, 2023
• Publicly Available Date: Jul 7, 2023
• Journal: Proceedings of the International Astronomical Union
• Print ISSN: 1743-9213
• Electronic ISSN: 1743-9221
• Publisher: Cambridge University Press
• Peer Reviewed: Peer Reviewed
• Volume: 3
• Issue: S250
• DOI: https://doi.org/10.1017/S1743921308020528
• Keywords: Astrophysics; stars: mass loss – stars: Population II – stars: rotation – supernovae: general – stars: Wolf-Rayet – Galaxy: evolution – gamma rays: bursts
• Public URL: https://keele-repository.worktribe.com/output/506749