Observed (left) and modelled (right) integrated intensity maps of H-MM1 in oH₂D⁺ (1₁₀ − 1₁₁) (top), N₂H⁺ (4 − 3) (middle), and DCO⁺ (5 − 4) (bottom). The model assumes a cosmic-ray ionisation rate per H₂ molecule of ${\zeta }_{{\text{H}}_2}=7.4\times {10}^{-18} {\text{s}}^{-1}$. The simulation time is 6.3 × 10⁵ yr. The oH₂D⁺ map is as predicted by the model, whereas the modelled abundances of N₂H⁺ and DCO⁺ are multiplied by 4.8 and 4, respectively, to reproduce the observed intensity levels. The intensity scale is $T_{\text{A}}^{*}$. The colour scales and the contours are the same as in Fig. 3. The squares indicate positions from which the spectra shown in Fig. C.2 are extracted.