Continuum JCMT SCUBA-2 image at 450 μm (grayscale), overlaid with the emission of NH₂D (1−0) (red), NHD₂ (magenta), H₂D⁺ (1−0) (blue), and N₂H⁺ (3−2) (green). Contours of N₂H⁺ are the same as in Fig. 10, while contours of NH₂D, NHD₂, and H₂D⁺ are drawn at (1σ, 1.5σ, 2σ, 3σ, 3.3σ), (1σ, 1.1σ), and (1σ, 1.2σ) respectively. The three yellow squares mark the positions of the extracted spectra for the analysis in Sect. 5.3.2.