From Roediger et al. (2015a). Snapshot of a high-resolution simulation of the hot atmosphere of an elliptical galaxy falling into a galaxy cluster. The bottom of the potential well is indicated with the black cross. The arrows show the velocity field of the fluid. Several features can be seen: the cold front at the peak with the KH rolls on the side, the remnant tail in the blue low-velocity area, and the stripped tail trailing behind.