Stellar wind yields of very massive stars

Higgins, Erin R; Vink, Jorick S; Hirschi, Raphael; Laird, Alison M; Sabhahit, Gautham N

Abstract

The most massive stars provide an essential source of recycled material for young clusters and galaxies. While very massive stars (VMS, 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 anti-correlations, such as C-N and Na-O, in globular clusters. We find that for VMS 95% of the total wind yields is produced on the main sequence, while only ∼ 5% 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.

Citation

Higgins, E. R., Vink, J. S., Hirschi, R., Laird, A. M., & Sabhahit, G. N. (in press). Stellar wind yields of very massive stars. Monthly Notices of the Royal Astronomical Society, 526(1), 534–547. https://doi.org/10.1093/mnras/stad2537

• Journal Article Type: Article
• Acceptance Date: Aug 31, 2023
• Online Publication Date: Aug 31, 2023
• Deposit Date: Sep 21, 2023
• Publicly Available Date: Sep 21, 2023
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 526
• Issue: 1
• Article Number: stad2537
• Pages: 534–547
• DOI: https://doi.org/10.1093/mnras/stad2537
• Keywords: stars: massive, stars: evolution, stars: abundances, stars: mass loss, stars: interiors, nuclear reactions, nucleosynthesis, abundances