Normalized intensities Ĩ_ij of CH⁺ rovibrational transitions v = 1 → 0, J → J + 1 following chemical-pumping while considering the observed distribution of H₂ and temperature. The red (resp. blue) line corresponds to the intensities of CH⁺ considering the temperature and H₂ population densities in the Bar (resp. in d203-506). The shaded areas indicate the range between the upper and lower limits as determined in Sect. 5.2.1. Red (resp. blue) crosses correspond to the normalized intensities of CH⁺ transitions observed in the Bar (resp. disk).