Distribution of the inner boundary of the stellar-halo-dominated region of our galaxies. The boundary is defined as the SMB radius, where stellar halo starts dominating over galaxy disk (SMB_0,SH; see Figure 8).The boundary is expressed in units of kiloparsecs (panel (a)) or R_e,maj (panel (b)). The distribution for the most prominent stellar halos with ellipticity <0.5 (SMB_e=0.5,SH) is shown in units of kiloparsecs (panel (c)) or R_e,maj (panel (d)). The sample is divided into low- and high-mass subsamples at a stellar mass of 10^10.4 M_⊙. Colored vertical dashed lines indicate the median values of each subsample. The median and central 68% range of the indices for the full sample, low- and high-mass subsamples are given in each panel. Colored dashed curves show the corresponding kernel density estimation profiles for each distribution, following the same color scheme as the histograms. See Section 4.4 for details.