Distribution of stellar mass and effective radius for cluster and field elliptical galaxies. Upper panel − distribution of the stellar mass ℳ_∗ (left) and of the effective radius R_e (right) for the 56 cluster elliptical galaxies (red shaded histograms) and the 31 elliptical galaxies in the GOODS-South field (blue shaded histograms). The lower panels show the comparison with the field elliptical galaxies selected in the COSMOS area (green histograms). The colored solid line marks the median values of the distributions (see text). The dotted line marks the reference values log ℳ_∗ = 11.1 M_⊙ and R_e = 4 kpc above which the distributions are significantly different. Lower panel − same as in the upper panel but in this case the distributions of the cluster ellipticals are compared with those of the elliptical galaxies selected from CANDELS (cyan histograms; see Sect. 2).