Stellar mass–size relation. Our sample is given with the same markers as in Fig. 8 and is plotted with R_e values from the i-band. Galaxies from the AMIGA sample with i-band R_e values are given in green, and the corresponding fit (see Sect. 5.1) is given in black. The H I-rich UDG sample from M20 is plotted with R_e values from the r-band and is denoted as red hexagons. Histogram on the top shows the distribution of stellar masses, with our sample plotted in purple and the AMIGA in green. The histogram on the right shows distributions of effective radii for M_⋆< 10⁹ M_⊙ in our and the AMIGA samples with the same color scheme.