Radial distribution of investigated galaxies represented by their cumulative fraction with respect to their distance to the BGG. Only galaxies within the solid circle in Fig. 9 (largest completely covered annulus) are taken into account as long as they obey the membership constraints of Sect. 3.2.2. Green: bright galaxies (M_R < −15  mag). Red: faint galaxies (M_R > −10.5  mag). Light blue: all galaxies brighter than M_R = −10.5 mag. The black solid line represents a uniform distribution as would be the case for background galaxies.