Wave-driven mass loss of stripped envelope massive stars: progenitor-dependence, mass ejection, and supernovae

TL;DR

This study investigates wave-driven mass loss in massive, hydrogen-poor stars, predicting small circumstellar media that minimally affect supernova light curves, but may cause observable shock breakout signatures.

Contribution

It provides the first comprehensive survey of wave heating effects across a range of progenitor masses and metallicities, linking stellar models to potential pre-supernova mass ejections.

Findings

Most models deposit less than 10^47 erg in the envelope.

Circumstellar masses are typically less than 0.01 solar masses.

Shock breakout phases may be observable in some supernovae.

Abstract

The discovery of rapidly rising and fading supernovae powered by circumstellar interaction has suggested the pre-supernova mass eruption phase as a critical phenomenon in massive star evolution. It is important to understand the mass and radial extent of the circumstellar medium (CSM) from theoretically predicted mass ejection mechanisms. In this work, we study the wave heating process in massive hydrogen-poor stars, running a suite of stellar models in order to predict the wave energy and pre-explosion time scale of surface energy deposition. We survey stellar models with main sequence progenitor masses from 20--70 $M_{\odot}$ and metallicity from 0.002 to 0.02. Most of these models predict that less than $\sim \! 10^{47} \, {\rm erg}$ is deposited in the envelope, with the majority of the energy deposited in the last week of stellar evolution. This translates to CSM masses less than $\sim \! 10^{-2} \, M_\odot$ that extend to less than $\sim \! 10^{14} \, {\rm cm}$, too small to greatly impact the light curves or spectra of the subsequent supernovae, except perhaps during the shock breakout phase. However, a few models predict somewhat higher wave energy fluxes, for which we perform hydrodynamical simulations of the mass ejection process. Radiative transfer simulations of the subsequent supernovae predict a bright but brief shock-cooling phase that could be detected in some type Ib/c supernovae if they are discovered within a couple days of explosion.