Projected stellar-mass surface density profiles for bulge (red diamonds) and disc components (blue diamonds) of two typical simulated ETGs. The regions of the discs that co-exist with spheroid components are highlighted (green diamonds). The best-fitted Sérsic profiles for the spheroid components (solid red lines) and the exponential profiles for the discs (dashed blue lines) are also included. The bulge effective radius (R_eff, calculated by using Eq. (6) in Sáiz et al. 2001), the R_hm and the R_d are depicted with red, black and blue arrows, respectively. In the upper panel, the inner disc follows the exponential profile (n ∼ 1.25) while in the lower panel, the same component follows the bulge profile (n ∼ 2.78). A variety of behaviours is detected, suggesting different contributions of processes such as collapse, mergers and secular evolution.