Same as Fig. 8, but here we compare the emission line luminosities (L′_line) of CO J:1–0 and CO J:7–6 for galaxies W and T, using kpc-scale apertures matched to the beam size of the line. The solid lines in the corresponding colour show the prediction if the galaxy integrated line flux ratio was valid over all individual apertures, and the dashed lines show the best linear fit to the datapoints.