is due to the fact that for Compton-thick AGN at energies $\lesssim 10\rm\,keV$ most of the X-ray emission is depleted. However, hard X-ray surveys as that of @Burlon:2011cr, which are much less biased by absorption, have found a normalization of the $\theta_{\mathrm{OA}}-L_{\mathrm{X}}$ relation consistent with that obtained at lower X-ray energies (see Fig.\[fig:tor\_CFL1\]). Our results also show that the X-ray Baldwin effect can be explained by a Compton-thin torus, and that larger values of $f_{\mathrm{obs}}$ would imply even lower average values of $N_{\rm\,H}^{\rm\,T}$, so that missing heavily obscured objects would not significantly affect our results. X-rays are also probably better suited to probe the material responsible for the iron K$\alpha$ line emission. The line can in fact be emitted by both gas and dust, and while the IR can probe only the latter, X-rays are able to infer the amount of both gas and dust. We thus conclude that for the purpose of our study the X-ray $\theta_{\mathrm{OA}}-L_{\mathrm{X}}$ relations are better suited than those extrapolated from IR observations.

It could be argued that the value of the hydrogen column density commonly used to determine the fraction of obscured objects (and thus as an indicator of the presence of the torus) 