Integrated intensity maps of the CO (2–1) (upper), CO (1–0) (middle), and ¹³CO (1–0) (lower) lines with velocity range from −14.5 to −6.5 km s^-1 superimposed on 24 μm emission. The contour levels start are at 3σ in steps of 5σ for CO (2–1) (), CO (1–0) (), and ¹³CO (1–0) (). The beam size of each subfigure is indicated at the bottom-left corner. The symbols “■”, letters (A, B, ..., and I), and ellipse indicate the positions of eight IRAS point sources, nine molecular clumps, and ring-like shell of the bubble, respectively. The unit of each colour bar is in MJy sr^-1. The dotted lines show the cutting direction of the slice profiles in Fig. 4 and the PV diagram in Fig. 5.