Molecular hydrogen pure rotational lines within the spectral range. The red profiles show line fitting using one or multiple Gaussian functions (dashed lines) in the case of line blending with other spectral features. The rest wavelength of the undetected lines is indicated by a slashed vertical line. In dark red we show the C₂H₂ rescaled model from Tabone et al. (2023) to show the features location. In orange, we show an eye-fit of a CO slab model. The S (2) line is blended with a C₂H₂ line. The S (6) and S (7) transitions fall in a crowded spectral region, and could not be identified. The S (8) transition is found in a region populated by several CO v = 1 – 0 P-branch lines, and cannot be identified either.