Same as Fig. 5, but showing only model B from that figure (green diamonds), plus the results of hypothetical giant impacts followed by photoevaporation (coloured circles). The colour-bar represents the final water mass fraction. The grey dots represent the observed exoplanet population as in Fig. 5. The yellow-bordered circles represent the planets that underwent the maximum envelope mass-loss due to a collision, and the black-bordered circles represent the mean values of envelope mass-loss for each family of collisions. The grey-bordered circles denote the bare cores that lost their envelopes completely either just after the collision or after photoevaporation.