Obtained from the data of F2008: a) Map of the CH₃CN(5–4) line emission (contours) tracing the HMC, overlaid on a map of the N₂H⁺(1–0) emission (from F2008) averaged over the main line (color scale). The black dots indicate the positions of the centimeter sources “a” (alias mm-core) and “b” (alias HMC), detected by Zapata et al. (2006). b) Maps of the blue- (solid white contours) and red-shifted (dashed black) emission of the HCO⁺(1–0) line overlaid on a map of the N₂H⁺(1–0) line velocity. The HCO⁺(1–0) maps are derived using the most extreme velocity channels (1.68 km s^-1 wide) at which emission was detected by F2008, centered at 55.8 km s^-1 and 62.5 km s^-1 for the blue- and red-shifted line, respectively. c) Map of the 3.3 mm continuum emission (contours) tracing the mm-core, overlaid on a map of the N₂H⁺(1–0) line FWHM.