PV-diagrams along the lines shown in Fig. 19, each with (from top to bottom) c-C₃ H₂ 2₁₂ → 1₀₁, CH₃ C₂H 5₀ → 4₀ and, overlapping, C₃H₂ 4₃₂ → 4₂₃ and H42α. The velocity scale refers to that of the CH₃C₂H line (see Sect. 4.6.2 and Table 1). Dark: low intensity; light gray: high intensity. Top left panel: cut A (see also Fig. 19) along the major axis from the northeast toward the southwest. Top right panel: cut B perpendicular to the major axis crossing the 710 km s⁻¹ peak from the southeast toward the northwest. Bottom left panel: cut C perpendicular to the major axis, central line. Bottom right panel: cut D perpendicular to the major axis crossing the 430 km s⁻¹ peak. A, B, C or D are displayed in the upper right corner of their respective panels. Blue contours: original data cube. Red contours: model data cube with constant vertical gradient in radial motion and finalrotation curve (see top two panels of Fig. 16). Contours: 0.1, 0.2, 0.4, 0.8 mJy beam⁻¹.