Binary Interaction Can Yield a Diversity of Circumstellar Media around Type II Supernova Progenitors

TL;DR

This study demonstrates that binary star interactions can produce diverse circumstellar media around Type II supernova progenitors, influencing the observable features of supernovae through different CSM structures.

Contribution

The paper introduces binary evolutionary simulations showing how binary interactions create varied CSM structures, a novel explanation for supernova diversity.

Findings

Binary mass transfer increases at Roche lobe overflow onset.

CSM density structures vary with orbital period, including shell-like and cliff-like features.

Characteristic CSM structures are within ~10^{17} cm and observable via long-term supernova observations.

Abstract

Recent observations of supernovae (SNe) have indicated that a fraction of massive stars possess dense circumstellar medium (CSM) at the moment of their core collapses. They suggest the presence of additional activities of the SN progenitor driving the enhancement of the mass-loss rate, and some physical processes attributing to single star's activities have been considered. In this study, we carry out binary evolutionary simulations of massive stars with the aim of investigating the CSM structure. We show that the mass-transfer rate in a binary can increase at the beginning of the Roche lobe overflow, and this enhancement would be associated with the structure of the CSM before the explosion. We also illustrate that depending on the orbital period of the binary, the density structure of the CSM can have a diverse distribution including shell-like and cliff-like structures. These characteristic structures appear within the lengthscale of $\sim 10^{17}\,{\rm cm}$ and could be traced by long-term observations of SNe, if the slow velocity of the CSM is assumed ($\sim 10\,{\rm km}\,{\rm s}^{-1}$). Our results highlight the importance of binary interaction in the aspect of reproducing the diversity of the CSM configuration.