Dust temperature of galaxies as a function of L_IR, as derived from our stacking analysis. In each panel, we give the Spearman correlation factor derived from our data points. Red dashed lines correspond to a second order polynomial fit to the data points of the 0.2 < z < 0.5 redshift bin. Hatched areas represented the regions of parameter space affected by incompleteness (see text and Fig. 5). The Chapman et al. (2003) derivation of the median and interquartile range of the relation observed at z ~ 0 is shown by solid and dot-dashed lines, linearly extrapolated to 10¹³ L_⊙. The lower panel of each redshift bin shows the offset between the median dust temperature of our data points and the dashed red line, in bins of 0.3 dex.