Ram pressure as a function of Mach number for the TNG50 subhalos in Fornax-like clusters. The small squares are color coded according to ∇_{O/H_diff}, while the gray circles are color coded according to the cluster-core distance of each subhalo. The circle size corresponds to the stellar mass of each subhalo as indicated in the right bar. The vertical dotted line indicates the threshold between supersonic (ℳ >  1) and subsonic (ℳ <  1) velocities.