Distributions of M_⋆ and L_150 MHz for the radio samples selected in this work. In the main panel, sources in the FinAGN and LowzROSF samples are denoted by red crosses and blue empty circles respectively. It should be noted that many blue circles are covered by the red crosses because of the overlapping parametric space. Top: M_⋆ distributions of the four samples. The FinAGN and LowzROSF samples are shown as red and blue histograms respectively. Right: L_150 MHz distributions of the two samples.