a) Overlay of the CO(3–2) ALMA intensity contours (levels as in Fig. 4a) on the Paα emission HST map (color scale as shown in counts s^-1pixel^-1). b) Same as a) but zooming in on the CND region. c) Overlay of the CO(6–5) ALMA intensity contours (levels as in Fig. 4c) on the HST Paα emission map (color scale as shown). The filled ellipses at the bottom right corners represent the CO beam sizes.