Comparison between fits with models of different complexity. Top panels: best fit of a simulated spectrum using the full model (left) and the simple model (right). The residuals are plotted below. Bottom panels: posteriors of Γ (left) and N_H (right) fitted with the full model (light purple) and the simple model (red). The dashed green lines show the input values. The blue points are medians of the posteriors with 68% credible intervals.