Molecular Environments of SNRs

TL;DR

This paper explores the molecular environments of supernova remnants, their interaction with molecular clouds, and implications for gamma-ray emissions, providing insights into supernova progenitors and cosmic ray acceleration.

Contribution

It introduces a correlation between wind bubble sizes and stellar masses, and discusses the role of molecular environments in gamma-ray production from SNRs.

Findings

SNRs are often in cavities of molecular gas.

A linear correlation exists between wind bubble sizes and stellar masses.

Molecular environments can probe gamma-ray emissions from cosmic ray interactions.

Abstract

There are about 70 Galactic supernova remnants (SNRs) that are now confirmed or suggested to be in physical contact with molecular clouds (MCs) with six kinds of evidence of multiwavelength observations. Recent detailed CO-line spectroscopic mappings of a series of SNRs reveal them to be in cavities of molecular gas, implying the roles the progenitors may have played. We predict a linear correlation between the wind bubble sizes of main-sequence OB stars in a molecular environment and the stellar masses and discuss its implication for supernova progenitors. The molecular environments of SNRs can serve as a good probe for the gamma-rays arising from the hadronic interaction of the accelerated protons, and this paper also discusses the gamma-ray emission from MCs illuminated by diffusive protons that escape from SNR shocks.