Large dust fractions can prevent the propagation of soundwaves

TL;DR

This paper identifies a critical dust fraction in astrophysical dust-gas mixtures where sound waves cannot propagate, providing an analytical benchmark for testing numerical solvers at high dust concentrations.

Contribution

It analytically characterizes a regime with large dust fractions preventing sound wave propagation, aiding the validation of numerical methods in astrophysics.

Findings

Sound waves are blocked above a critical dust fraction.

Analytical description of the dust fraction threshold.

Benchmarking tool for numerical solvers at high dust content.

Abstract

Dust plays a central role in several astrophysical processes. Hence the need of dust/gas numerical solutions, and analytical problems to benchmark them. In the seminal dustywave problem, we discover a regime where sound waves can not propagate through the mixture above a large critical dust fraction. We characterise this regime analytically, making it of use for testing accuracy of numerical solvers at large dust fractions.