IR $\theta_{\mathrm{OA}}-L_{\mathrm{X}}$ relationship of @Maiolino:2007bh the values allowed are in the range $22.9 \lesssim \log N_{\rm\,H}^{\rm\,T} \lesssim 23$. A similar result is obtained studying the $A/B$ chi-squared contour plot of our fit to the [*Chandra*]{}/HEG data. Using the model of @Brightman:2011oq to simulate the X-ray Baldwin effect in the Seyfert regime we obtained a range of $N_{\rm\,H}^{\rm\,T}$ consistent with that found using the model of @Ikeda:2009nx ($23.2 \lesssim \log N_{\rm\,H}^{\rm\,T} \lesssim 23.3$). The lower values of $N_{\rm\,H}^{\rm\,T}$ needed to explain the X-ray Baldwin effect using the relationship of @Maiolino:2007bh are due to the larger values of $f_{\mathrm{obs}}$ (and thus of $\theta_{\mathrm{OA}}$) predicted by Eq.\[Eq:Maiolino\]. This is again due to the fact that $EW$ depends on both $N_{\rm\,H}^{\rm\,T}$ and $\theta_{\mathrm{OA}}$, thus increasing the latter one would obtain lower values of the former.

Quasar regime {#sec:Qsoregime}
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To study the behavior of $B$ in the quasar regime, we fitted the simulated data using Eq.\[eq:fit\_XBE\] for each value of $N_{\rm\,H}^{\rm\,T}$ for luminosities $L_{\mathrm{X}}>L_{\mathrm{X}}^{\mathrm{Q}}$. Our simulations show that $EW$ decreases more steeply in the quasar regime than at lower luminosities for the $\theta_{\mathrm{OA}}-L_{\mathrm{X}}$ relationships of @Hasinger:2008ve and @Maiolino:2007bh, with values of the slope of $B\lesssim -0.3$ (left panel of Fig.\[fig:interc\_sy\_2\]). The slopes obtained by 