Channel maps of methyl cyanide J = 13₃−12₃ emission integrated over the velocity ranges indicated on each panel. Contours are plotted from 5 to 70 in 5 K km s^-1 intervals. The various sources indicated on the maps are as described in Fig. 1. The direction of the SiO outflow from source I (e.g. Plambeck et al. 2009) is indicated by the blue arrow. The extended emission appears at velocities of 7−12 km s^-1, typical of the ridge.