PREPRINT
A136143C-0180-44A9-B2D6-7B2A527D7CE2

# Evolution of massive stars with new hydrodynamic wind models

A. C. Gormaz-Matamala, M. Curé, G. Meynet, J. Cuadra, J. H. Groh, L. J. Murphy
arXiv:2207.04786

Submitted on 11 July 2022

## 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, $v\left(r\right)$, and the line-acceleration, ${g}_{\text{line}}$, 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 ${M}_{\text{ZAMS}}=25,40,70$ and $120\phantom{\rule{0.167em}{0ex}}{M}_{\odot }$ and metallicities $Z=0.014$ (Galactic), $Z=0.006$ (LMC), and $Z=0.002$ (SMC). Our new derived formula for mass-loss rate predicts a dependence $\stackrel{˙}{M}\propto {Z}^{a}$, where $a$ is not longer constant but dependent on the stellar mass: ranging from $a\sim 0.53$ when ${M}_{\ast }\sim 120\phantom{\rule{0.278em}{0ex}}{M}_{\odot }$, to $a\sim 1.02$ when ${M}_{\ast }\sim 25\phantom{\rule{0.278em}{0ex}}{M}_{\odot }$. We found that models adopting the new recipe for $\stackrel{˙}{M}$ 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 ${M}_{\text{ZAMS}}=70$ and 120 ${M}_{\odot }$ at solar metallicity, where we found self-consistent tracks are $\sim 0.1$ dex brighter and keep extra mass up to 20 ${M}_{\odot }$, 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 ${}^{26}$Al in the core and the surface of the star. Since ${\stackrel{˙}{M}}_{\text{sc}}$ are weaker than the commonly adopted values for evolutionary tracks, self-consistent tracks predict a later modification in the abundance number of ${}^{26}$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.

## Preprint

Comment: Accepted for publication in Astronomy & Astrophysics

Subjects: Astrophysics - Solar and Stellar Astrophysics; Astrophysics - Astrophysics of Galaxies