Evolution of the average rest-frame SEDs with NRK for the 24 μm-selected sample. Each SED is reconstructed by using all the available COSMOS pass-bands. Galaxies are divided in bins of NRK (columns of the figure), redshift (rows) and stellar mass (blue, green and red symbols in each panel). The number of galaxies for each sample is shown in each panel. We also report the logarithm of the mean ratio FIR/FUV as an indicative value of the IRX. In the first bin of NRK (i.e., first column of the figure) we overplot the dust-free template of young star-forming galaxy. In the other three bins of NRK (i.e., three right-most columns) we overplot the same template, but with increasing reddening excess (E(B − V) = 0.2, 0.4 ,0.6, respectively), assuming the Calzetti et al. (2000) attenuation law (solid, black line) and the SMC extinction law (dashed, gray line). The three vertical bands refer to the bandwidths of the NUV, r and K filters.