Model expectations at 150 MHz. Left panel: expected fraction of clusters with RHs with ν_s ≥ 150 MHz as a function of the cluster mass. Middle panel: expected fraction of RH with very steep radio spectra (ν_s < 600 MHz) as a function of the cluster mass. Right panel: RH luminosity function at ν_o = 150 MHz. In all panels, the lines refers to z = 0 − 0.1 (black line), 0.2 − 0.3 (blue line), and 0.5 − 0.6 (red line).