Strange mode instabilities and mass-loss in evolved massive primordial stars

Abstract

A linear stability analysis of models for evolved primordial stars with masses between 150 and 250 M${}_{\odot }$ is presented. Strange mode instabilities with growth rates in the dynamical range are identified for stellar models with effective temperatures below log T${}_{\mathrm{eff}}$ = 4.5. For selected models the final fate of the instabilities is determined by numerical simulation of their evolution into the non-linear regime. As a result, the instabilities lead to finite amplitude pulsations. Associated with them are acoustic energy fluxes capable of driving stellar winds with mass-loss rates in the range between 7.7 $\times$ 10${}^{-7}$ and 3.5 $\times$ 10${}^{-4}$ M${}_{\odot }$ yr${}^{-1}$.

11 pages, 14 figures, 1 table, Accepted for publication in MNRAS