Magnitude-size diagram. Left panel: magnitude versus effective radius for the VEGAS-SSS field centered on NGC 3115. Color-coding for black and gray dots is as in previous figures, with the addition of the best sample selection (red empty circles). Yellow regions show the mean loci of the labeled SSS classes. The number of UCD and GC candidates, N_UCD and N_GC, for the reference and best sample (given in parenthesis) are also reported. Right panel: as left panel, but only sources with R_gal ≤ R_bg are plotted. The blue arrow shows the direction in which the points are shifted if the object lies at larger distance. We included the ACS sample using green symbols: GCs shown with circles, UCDs with squares. For the ACS sample, spectroscopically confirmed GCs from Arnold et al. (2011) are plotted as solid symbols.