Predictions of radio counts of star forming galaxies for SKA precursors

We extended recent semi-analitycal galaxy formation models, that fitted the far- infrared (FIR) to millimeter wave luminosity functions and ultraviolet (UV) luminosity functions up to high redshifts, in order to take into account additional UV data and Hα luminosity functions. The latters are tracers of star formation in evolved galaxies at low redshifts. Using the relations between star formation rate (SFR) and radio (synchrotron and free-free) emission, we obtained predictions for the counts of star-forming galaxies down to sub-nJy fluxes. These will be very useful for the new generation of radio telescopes, thanks to which it will be possible to investigate smaller and smaller radio fluxes (down to nJy), making the detection of little SFR possible