Stellar wind yields of very massive stars
Abstract
The most massive stars provide an essential source of recycled material for young clusters and galaxies. While very massive stars (VMSs, M>100 $\rm {\rm M}_{\odot }$) are relatively rare compared to O stars, they lose disproportionately large amounts of mass already from the onset of core H-burning. VMS have optically thick winds with elevated mass-loss rates in comparison to optically thin standard O-star winds. We compute wind yields and ejected masses on the main sequence, and we compare enhanced mass-loss rates to standard ones. We calculate solar metallicity wind yields from MESA stellar evolution models in the range 50-500 $\rm {\rm M}_{\odot }$, including a large nuclear network of 92 isotopes, investigating not only the CNO-cycle, but also the Ne-Na and Mg-Al cycles. VMS with enhanced winds eject 5-10 times more H-processed elements (N, Ne, Na, Al) on the main sequence in comparison to standard winds, with possible consequences for observed anticorrelations, such as C-N and Na-O, in globular clusters. We find that for VMS 95 per cent of the total wind yields is produced on the main sequence, while only ~ 5 per cent is supplied by the post-main sequence. This implies that VMS with enhanced winds are the primary source of 26Al, contrasting previous works where classical Wolf-Rayet winds had been suggested to be responsible for galactic 26Al enrichment. Finally, 200 $\rm {\rm M}_{\odot }$ stars eject 100 times more of each heavy element in their winds than 50 $\rm {\rm M}_{\odot }$ stars, and even when weighted by an IMF their wind contribution is still an order of magnitude higher than that of 50 $\rm {\rm M}_{\odot }$ stars.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- November 2023
- DOI:
- 10.1093/mnras/stad2537
- arXiv:
- arXiv:2308.10941
- Bibcode:
- 2023MNRAS.526..534H
- Keywords:
-
- stars: massive;
- stars: evolution;
- stars: abundances;
- stars: mass-loss;
- stars: interiors;
- nuclear reactions;
- nucleosynthesis;
- abundances;
- Astrophysics - Solar and Stellar Astrophysics;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- Accepted for publication in MNRAS. 14 pages, 10 figures