Integrated intensity maps of the J_K = 18_K − 17_K emission of the CH₃CN (green contour) and CH₃¹³CN (magenta contour) lines. The black dashed contour corresponds to the absorptions region seen in the ¹³CO (3−2) line. The thin black contour represents the 7σ level of the uniform weighting 890 μm continuum emission map (Fig. 2b). All the transitions, except the CH₃CN K  =  0, 1, and 2 components, are not blended with other lines (see Fig. 11 for the spectrum). The contour intervals are spaced by 2σ and start from the 3σ level. In the CH₃CN maps, we do not plot contours above the 17σ level to prevent saturation of the maps. The 1σ rms noise levels are 6.3, 1.4, 1.3, 0.33, and 0.17 mJy beam^-1 km s^-1 for the CH₃CN (18−17) K = 0 to 2 emission, K = 3, K = 4, and CH₃¹³CN (18−17) K = 2, and K = 6, respectively.