Surface-mass-density profiles as a function of projected distance from cluster’s centre normalised by the projected half-mass radius (R_h) of the total cluster (see Sect. 2 for a complete definition). The profiles are shown at a few representative times in the Delta0 model. All densities are normalised by the central bin of the total surface-mass density (FG + SG). Time is normalised by the initial half-mass relaxation time of the cluster, t_rh,i. The difference between the profiles of the two generations is gradually erased as the system evolves.