Demonstration of the Monte-Carlo method on the 4 pixels of the R9 map. The grey ellipses represent the unperturbed observations and their uncertainties: the filter band widths on the x direction; the  ± 1σ error bars on the y direction (dark grey); and the  ± 3σ error on the y direction (concentric light grey ellipse). The color lines show the N_MC = 300 model fits to the perturbed fluxes. We used the “standard model” for the demonstration. Some points (like MIPS_70 μm) appears shifted from the models because of the color correction. The two shortest wavelengths of the  [1,4]  pixel are poorly fitted since the IRAC_3.6 μm is only an upper limit. This might be the result of oversubtraction of point sources in this low surface brightness region. However, this discrepancy affects only the level of the independent stellar contribution. It does not affect the longer wavelength fit.