Cluster-centric distance as a function of look-back time of those red subhalos in our sample which have an infall time ≥ 6 Gyr. It is color coded by the ram-ness parameter defined in Equation (5). The dashed curve shows the virial radius R₂₀₀ of the group. The vertical dotted line marks the the infall time of the subhalo. The bottom panel shows some snapshots of the gas distribution at a specific time (marked by downward arrows in the main panel) where tentacles of gas are clearly seen.