3.6 μm central surface brightnesses (μ_0, 3.6) vs. stellar mass. Left panel: μ_0, 3.6 derived from single-component 2D decompositions, while the right panel shows μ_0, 3.6 derived by fitting generalized single Sérsic functions to each galaxy’s radial surface brightness profile (fixed isophotal parameter, Δr = 2″, with aperture correction applied; see Sect. 3.2). Galaxies with fitted n > 7 are circled in blue. Linear fits to the two distributions are shown via the red dashed lines, excluding galaxies with ℳ_*/ℳ_⊙ < 8 and fitted n > 7. Points lying above the axis limits are shown as up-pointing arrows; each of these had fitted n > 7. ETG data points are multicolored (with dwarfs in cyan), while LTGs are shown in gray.