Left panel: dust continuum emission map (contours) overlaid on the map of the CH₃ CN (12–11) K = 2 emissionaveraged over the velocity range 92 to 102 km s⁻¹ (colors). Contours are 7.5, 30, 75, 120, 165, and 232.5 mJy beam⁻¹. The white crosses indicate the positions of the two compact free-free continuum sources detected by Cesaroni et al. (2010). The synthesized beam is shown in the lower right-hand corner. Right panels: spectra of the CH₃ CN K = 0 to 6 and CH₃¹³CN K = 0 to 2 toward the absorption dip, that is, toward the dust continuum peak. The upper right panel zooms in on the CH₃ CN K = 2 spectrum.