The infrared-radio correlation of star-forming galaxies is strongly M ⋆ -dependent but nearly redshift-invariant since z ∼ 4

Over the past decade, several works have used the ratio between total (rest 8−1000 μ m) infrared and radio (rest 1.4 GHz) luminosity in star-forming galaxies ( q IR ), often referred to as the infrared-radio correlation (IRRC), to calibrate the radio emission as a star formation rate (SFR) indicator. Previous studies constrained the evolution of q IR with redshift, finding a mild but significant decline that is yet to be understood. Here, for the first time, we calibrate q IR as a function of both stellar mass ( M ⋆ ) and redshift, starting from an M ⋆ -selected sample of > 400 000 star-forming galaxies in the COSMOS field, identified via ( NUV − r )/( r − J ) colours, at redshifts of 0.1