Inhibited destruction of dust by supernova in a clumpy medium

TL;DR

This study shows that in a clumpy medium, supernova shock waves destroy less dust, with more dust surviving in highly inhomogeneous environments, affecting the net dust evolution in galaxies.

Contribution

It demonstrates how medium inhomogeneity influences dust survival during supernova shocks, highlighting the importance of clumpiness in dust destruction models.

Findings

Dust destruction is inhibited in more inhomogeneous media.

Surviving dust mass saturates after several radiative times, regardless of gas density.

Clumpy media have smoother dust size and thermal phase distributions.

Abstract

The decrease rate of dust mass due to strong shock waves ($v_s\geq 150$ km s$^{-1}$) from supernovae (SNe) estimated for the Milky Way interstellar medium significantly exceeds the overall production rate by both asymptotic giant branch stars and core collapse SNe. The interplay between the production and destruction rates is critically important for evaluation of the net dust outcome from SNe at different conditions. In light of this, we study the dynamics of initially polydisperse dust grains pre-existing in an ambient medium swept up the SN shock front depending on magnitude of inhomogeneity (clumpiness) in the medium. We find that dust destruction inside the bubble is inhibited in more inhomogeneous medium: the larger amount of dust survives for the higher dispersion of density. This trend is set by the interrelation between radiative gas cooling and dust sputtering in different environment. After several radiative times the mass fraction of the survived dust saturates at the level almost independent on the gas mean density. We note that for more clumpy medium the distributions of dust over thermal phases of a gas inside the bubble and over sizes are smoother and flatter in comparison with those in a nearly homogeneous medium.