Deuteration map of HC₃N. Only pixels above the 3σ level of the respective integrated intensities are plotted. The dashed line contours represent 30%, 50%, and 90% of the H₂ column density peak derived from Herschel maps (Spezzano et al. 2016). The circle in the bottomleft corner indicates the beam size of the IRAM 30m telescope (31″). The markers in black represent the dust peak (triangle) and the molecular emission peaks of CH₃OH (diamond), CH₃CCH (star), and c-C₃H₂ (plus sign). The corresponding D/H error map is shown in Fig. A.1.