Observed (black points) and model (green solid line) surface-brightness radial profiles of the sample galaxies. The observed radial profiles were obtained by fitting ellipses to the isophotes of the K_s-band images. The model profiles follow a Sérsic law. These profiles were not corrected for cosmological dimming, K- or evolutionary corrections. The short vertical lines mark the effective radius. Semi-major axes of fitted ellipses are given in arcsec (bottom) and kpc (top). The inset in the upper panels shows the surface brightness in logarithmic scale to enhance the quality of the fit in the inner regions. The residuals of the fit are represented by a gray region in the lower panels.