Best-fit LTE model for NO and C₂H at 5 μm, with f_bg = 1. The top panel shows the absorption model with the continuum and PAH emission, the middle panel shows the absorption spectrum, and the bottom panel shows the residuals on the absorption spectrum. Pink shaded areas indicate the spectral regions used in the fit. The grey shaded area in the bottom panel indicates the 68% interval of the residuals. All model spectra are rebinned onto the spectral axis of the observed spectrum to enable a more precise visual comparison to the data.