Numerical simulations of supernova remnants in turbulent molecular clouds

TL;DR

This study uses 3D hydrodynamic simulations to explore how supernova remnants interact with turbulent molecular clouds, revealing how turbulence and density affect observable properties and providing insights into the structure of the surrounding medium.

Contribution

It introduces detailed simulations of SNRs in turbulent MCs, linking turbulence levels to observable SNR features and estimating ambient densities and turbulence in specific observed remnants.

Findings

SNR properties are mainly influenced by the mean density of the medium.

Higher turbulence results in lower interior temperature and dimmer X-ray emission.

Estimated ambient densities for observed SNRs W44, W28, and IC 443.

Abstract

Core-collapse supernova (SN) explosions may occur in the highly inhomogeneous molecular clouds (MCs) in which their progenitors were born. We perform a series of 3-dimensional hydrodynamic simulations to model the interaction between an individual supernova remnant (SNR) and a turbulent MC medium, in order to investigate possible observational evidence for the turbulent structure of MCs. We find that the properties of SNRs are mainly controlled by the mean density of the surrounding medium, while a SNR in a more turbulent medium with higher supersonic turbulent Mach number shows lower interior temperature, lower radial momentum, and dimmer X-ray emission compared to one in a less turbulent medium with the same mean density. We compare our simulations to observed SNRs, in particular, to W44, W28 and IC 443. We estimate that the mean density of the ambient medium is $\sim 10\,$cm$^{-3}$ for W44 and W28. The MC in front of IC 443 has a density of $\sim 100\,$cm$^{-3}$. We also predict that the ambient MC of W44 is more turbulent than that of W28 and IC 443. The ambient medium of W44 and W28 has significantly lower average density than that of the host giant MC. This result may be related to the stellar feedback from the SNRs' progenitors. Alternatively, SNe may occur close to the interface between molecular gas and lower density atomic gas. The region of shocked MC is then relatively small and the breakout into the low density atomic gas comprises most of the SNR volume.