Slab model spectrum comparing CO₂ emission (black) and ¹³CO₂ emission (cyan) with the H₂O emission (blue) and OH emission (magenta) at a resolving power of 2200. Slab models uses the parameters fitted by Salyk et al. (2011b) for AS 205 (N) (see Table F.1). The large number of strong water lines strongly contaminates the CO₂ spectrum. All spectra are normalized to the peak of the CO₂ emission. A lot of single water lines are up to four times as strong as the peak of the CO₂ 15 μm feature. The ¹³CO₂ and OH fluxes have been multiplied by a factor of 10 for clarity.