Logarithmic ratio between AGN-related and SF-related radio emission ( and , respectively), as a function of ℳ_*, coloured by redshift. Each data point (square) represents the ratio between average AGN and SF luminosities for ℳ_*-selected SFGs in the same bin. The dividing threshold between AGN and SF-dominated regions (dashed black line) is crossed at ℳ_* ∼ 10¹¹ ℳ_⊙, above which galaxy radio emission is mainly powered by AGN jets. Filled squares mark bins in which the mean is above the 5σ VLA 3 GHz luminosity limit (, scaled to 1.4 GHz). Coloured lines indicate the best-fit ratio (solid) from Eq. (10).