The circumgalactic medium surrounding galaxies can be a thermally unstable gas, meaning that initially small isobaric perturbations grow, ultimately forming cold, small clouds. This 2D simulation shows the formation of gas structure due to TI in a stratified atmosphere; this dense gas then falls onto the galaxy (downwards). The domain shown is 86 kpc, resolved by 4096 cells. The four panels from left to right show a time progression, from shortly after the initial condition, to roughly 17 cooling timescales.

Methods: ENZO code