Simulated MR spectrum assuming a flux level of 200 mCrab (with an exposure of 10 ks), using the nominal ARF (i.e. without applying any reconstruction) in red and the reconstructed ARF in green. The black dashed line corresponds to the model obtained by fitting the spectrum using the nominal ARF, fixing N_H and Γ to the input values, leaving only the normalization free. The corresponding residuals are shown in the bottom panel (red points). In the case of the reconstructed ARF, the residuals are shown using the input parameters from the simulations, without performing any fit. The spectra are rebinned for clarity reasons.