Same as Fig. 4 but for the C¹⁸O (2–1) emission. The integrated velocity ranges are high velocities of V_LSR = 1–4 and 8.6–13.4 km s⁻¹, medium velocities of V_LSR = 4–5.6 and 7.8–8.6 km s⁻¹, and low velocities of V_LSR = 5.6–7 and 7–7.8 km s⁻¹. Contour levels are from 5σ and increase in steps of a factor two in panels a and b, and those are 10σ, 15σ, 20σ, 40σ, and 80σ in panel c. 1σ levels of the integrated blue- and redshifted emission are 4.2 and 5.9 mJy beam⁻¹ km s⁻¹ in panel a, both 3.2 mJy beam⁻¹ km s⁻¹ in panel b, and 3.7 and 2.6 mJy beam⁻¹ km s⁻¹ in panel c. The positions to extract spectra, which are shown in Fig. 7, are labeled as A–D in panel b.