Integrated intensity maps of the observed transitions. The grey solid line contours indicate the 30%, 70%, and 90% level of the peak integrated intensity. The dashed line contours represent 30%, 50%, and 90% of the H₂ column density peak derived from Herschel maps (Spezzano et al. 2016). The markers in blue represent the dust peak (triangle) and the molecular emission peaks of CH₃OH (diamond), CH₃CCH (star), and c-C₃H₂ (plus sign), where emission spectra (shown in Fig. 2) are extracted within a circular aperture with a diameter corresponding to the telescope beam. The white circle in the bottom-left corner indicates the beam size of the IRAM 30 m telescope (31″).