Results of the parameters sampling for one of the mock observation of Sect. 4.1. Upper panel: best-fit SED (black solid line) and components (coloured lines) compared to the mock observation data (empty blue markers); 1-σ and 2-σ confidence around the mean of the samples is also shown with grey shaded areas. Lower panel: residuals with respect to the best-fit sample (black); mean and 1-/2-σ confidence regions are also shown with a grey solid line and shaded areas, respectively.