KS test for observed late-type galaxies (gray) and dispersion-dominated (κ_rot <  0.5) simulated (red, green) DGs with stellar masses between 5 × 10⁷ M_⊙ and 10⁹ M_⊙. The thick lines and the displayed d_a- and P_a-values refer to the real stellar half-mass radius distribution of the Illustris-1 simulation. The thin lines and the d_b- and P_b-values refer to a distribution in which all radii in the Illustris-1 simulation are divided by two (see text). The observational data are a subset of the catalog from Dabringhausen & Fellhauer (2016) including all galaxies from the Fornax, Hydra, and Centaurus cluster catalog with stellar masses between 5 × 10⁷ M_⊙ and 10⁹ M_⊙.