Top panels: normalised distribution of the X-ray power-law photon index and the observed 2–10 keV flux. Bottom panels: normalised distribution of the intrinsic absorption and the rest-frame 2–10 keV luminosity corrected for both Galactic and intrinsic absorption. The error points in the intrinsic absorption distribution show the distribution for the sample given by Tozzi et al. (2006). Solid-line shaded and empty histograms show the distribution for the IR power-law and IR no power-law populations, respectively. The dashed-line empty histogram shows the distribution for the entire sample. All the values are given by the best fitted model (see Sect. 3).