Dust distribution in circumstellar shells

TL;DR

This paper uses numerical simulations to study how dust of different sizes distributes in circumstellar shells, revealing that large dust grains are weakly coupled to gas and can serve as tracers for validating hydrodynamical models.

Contribution

It introduces a detailed simulation approach that accounts for dust grain size effects in circumstellar shell dynamics, providing new insights into dust-gas coupling.

Findings

Large dust grains are weakly coupled to gas.

Small dust grains are strongly coupled to gas.

Dust distribution differences can help validate models.

Abstract

We present numerical simulations of the hydrodynamical interactions that produce circumstellar shells. These simulations include several scenarios, such as wind-wind interaction and wind-ISM collisions. In our calculations we have taken into account the presence of dust in the stellar wind. Our results show that, while small dust grains tend to be strongly coupled to the gas, large dust grains are only weakly coupled. As a result, the distribution of the large dust grains is not representative of the gas distribution. Combining these results with observations may give us a new way of validating hydrodynamical models of the circumstellar medium.