Position-velocity (PV) diagrams along the primary axis (first row) and the secondary axis (second row) of the quadrupolar flow. Arm-shape structures are drawn with dashed orange lines. The disk spatial extension is given by the black vertical line. The vertical dotted lines correspond to the core υ_LSR = 6.6–6.8 km s⁻¹ (Wu et al. 2019) and the disk υ_LSR = 7.37 km s⁻¹, the horizontal to the 0″ offset. Offsets are positive toward the north. First column: HC₃N emission. The contour levels are [5, 8, 11, 14, 17]σ where σ = 1.45 mJy beam⁻¹. Second column: C₂H emission. The contour levels are [5, 8, 12, 17, 23, 30]σ where σ = 1.39 mJy beam⁻¹. Third column: CS emission. The contour levels are [10, 20, 40, 60, 80, 100, 130]σ where σ = 1.44 mJy beam⁻¹.