Combined radio-SFR plots corrected for the CRE calorimetric efficiency at 144 (panel a) and 1365 MHz (panel b). We show the radio Σ_SFR, which we have corrected with the parametrisation of the calorimetric efficiency as function of the radio spectral index, as function of the hybrid Σ_SFR. The 1:1 Condon’s relation is shown as blue line. Data points are coloured according to the 144–1365 MHz radio spectral index. Yellow stars show mean values. The best-fitting power-law relations are not shown as they are virtually in agreement with Condon’s relation (see Table 2 for details).