Molecular clouds (MC) are the birthplace of stars. This made them a prime object of interest for many observers. But the gas they are mostly composed of is more often than not, hard to observe directly. As a proxy, we look for the dusts present in these clouds. Even if they represent only a fraction of the mass of the MC (up to 1%), they have a strong radiation field associated to them.
An common assumption is that these dusts are locked in the dynamics of the gas of the MC, and that observing the spatial distribution of the dusts gives direct information on the distribution of the gas. But this assumption is more and more challenged in recent years, with simulations pointing out to the fact that strong dynamics, like shocks, may dissociate gas and dust.
In our present work we have study the destruction of a dusty molecular cloud by shocks. We show how the dust, in the expected concentration found in MC, does not play a significant role for the dynamics. The dust is nonetheless redistributed and the picture we obtain is drastically different from one that would result from observing the gas directly. MCs are simulated with MPI-AMRVAC and emissions from the dust are obtain with SKIRT.