Kinematic analysis of the N–S ridge. Top-left panel: integrated intensity map of HC₅N (color scale) overlaid with HC₃N contours, as in Fig. 3. The white star and circle mark sources A and B, respectively. The white ellipse in the bottom-right corner shows the beam size. Top-right panel: Cut used to make the PV diagram with source A located at offset 0 (indicated by the orange rectangle in the top-left panel). The vertical dotted lines mark the systemic velocity of A and B. The white and magenta lines show free-fall and infall curves, respectively. The velocity range with E–W-outflow-related emission is shown as the shaded area (4.5 and 5.1 km s⁻¹) (Fig. B.1). Bottom row: HNC, HC₃N, and HC₅N spectra extracted from the corresponding positions marked in the top-left panel. The changes in peak velocity and line shape are signatures of moving gas. HNC and HC₃N show an inverse P Cygni profile along the middle of the N–S ridge (Position 2, ~20′′ from source A), indicating infall. Near source A (Position 4, ~5′′) HNC shifts to a P Cygni profile, consistent with the presence of outflow in this region.