Position-velocity diagram for CCH 1_2,2–0_1,1, HC₃N (9–8) (in magenta contours) in comparison to that of SiO (2–1) (gray filled contours), along the U, M, and L cuts as illustrated in panel b of Fig. 9. The V_LSR of MM2 and MM3 are indicated as green horizontal lines (93.9 km^–1 and 91.3 km^–1). The vertical dotted line and shaded regions follow those as in Fig. 9. The peak velocity along the spatial offset for SiO (2–1) and the respective molecular line (that have extended emission) in each plot are indicated as black and magenta lines.