Average radial profile of the CO-to-H₂ conversion factor (α_CO), for different transitions (shown in the legend on the right). The x-axis is plotted in log scale. The solid lines represent the median α_CO, averaged across the entire galaxy sample shown in each panel. The shaded regions encompass the 16th and 84th percentiles of the values at each radius. The columns and rows indicate the same redshift, and stellar mass bins as in Fig. 3.