Overview of the spectral region between 13.2 and 16 μm for all XUE sources. The lowermost spectrum shows the most prominent molecules in this region: HCN at 400 K and 10¹⁶ cm⁻² (dark green), H₂O at 400 K and 2.2 × 10¹⁶ cm⁻² (magenta), C₂H₂ at 400 K and 2.2 × 10¹⁶ cm⁻² (light green), CO₂ at 400 K and 10¹⁶ cm⁻² (red), H₂O at 850 K and 10¹⁸ cm⁻² (blue), and ¹³CO₂ 400 K and 10¹⁶ cm⁻² (dark red).