English

Evolution of massive stars with new hydrodynamic wind models

Solar and Stellar Astrophysics 2022-09-21 v1 Astrophysics of Galaxies

Abstract

Here we present evolutionary models for a set of massive stars, introducing a new prescription for the mass-loss rate obtained from hydrodynamical calculations in which the wind velocity profile, v(r)v(r), and the line-acceleration, glineg_\text{line}, are obtained in a self consistently way. Replacing mass-loss rates at the Main Sequence stage from the standard Vink's formula by our new recipe, we generate a new set of evolutionary tracks for MZAMS=25,40,70M_\text{ZAMS}=25,40,70 and 120M120\,M_\odot and metallicities Z=0.014Z=0.014 (Galactic), Z=0.006Z=0.006 (LMC), and Z=0.002Z=0.002 (SMC). Our new derived formula for mass-loss rate predicts a dependence M˙Za\dot M\propto Z^a, where aa is not longer constant but dependent on the stellar mass: ranging from a0.53a\sim0.53 when M120  MM_*\sim120\;M_\odot, to a1.02a\sim1.02 when M25  MM_*\sim25\;M_\odot. We found that models adopting the new recipe for M˙\dot M retain more mass during their evolution, which is expressed in larger radii and consequently more luminous tracks over the Hertzsprung-Russell diagram. These differences are more prominent for the cases of MZAMS=70M_\text{ZAMS}=70 and 120 MM_\odot at solar metallicity, where we found self-consistent tracks are 0.1\sim0.1 dex brighter and keep extra mass up to 20 MM_\odot, compared with the classical models using the previous formulation for mass-loss rate. Moreover, we observed remarkable differences for the evolution of the radionuclide isotope 26^{26}Al in the core and the surface of the star. Since M˙sc\dot M_\text{sc} are weaker than the commonly adopted values for evolutionary tracks, self-consistent tracks predict a later modification in the abundance number of 26^{26}Al in the stellar winds. This new behaviour could provide useful information about the real contribution of this isotope from massive stars to the Galactic interstellar medium.

Keywords

Cite

@article{arxiv.2207.04786,
  title  = {Evolution of massive stars with new hydrodynamic wind models},
  author = {A. C. Gormaz-Matamala and M. Curé and G. Meynet and J. Cuadra and J. H. Groh and L. J. Murphy},
  journal= {arXiv preprint arXiv:2207.04786},
  year   = {2022}
}

Comments

Accepted for publication in Astronomy & Astrophysics

R2 v1 2026-06-25T00:48:32.489Z