Comparison between the observed (red) and best-fit synthetic (black) spectra in the wavelength range 12 − 16 μm. The relative difference between model and observation (F_ν, obs − F_ν, mod)/F_ν, obs is shown in the bottom panel. The gray shaded regions indicate the data points that contribute to the χ² calculation in fitting the water spectrum. Prominent emission lines from other molecules are shown.