Parametrisation of the MAHs. The two top panels present the assembly histories of the whole sample, colour-coded according to the formation redshift z_form (left) and the episodicity parameter α_MAH (right-hand side panel). The two bottom panels describe the distribution of these parameters in the {PC₁,  PC₂} space, accounting for the maximum variance with two linearly uncorrelated components. The colour coding of the dots is the same as represented in their respective top panels.