Distribution of R_e-normalized SSD values as a function of R_e for JType = 2 (red stars), undisturbed (green triangles), and gravitationally interacting (blue diamonds) galaxies. Empty symbols indicate galaxies for which R_e was estimated using the empirical R_e − M_★ relation from Franchetto et al. (2020). Solid lines represent the median SSD values for each galaxy type, while the shaded regions correspond to the interquartile range (25%–75%). Dashed lines indicate 25% and 75% of each galaxy type. The SSD value distributions, along with their medians and interquartile ranges, are also shown in the histogram on the right-hand panel.