Velocity fields of the CND for HCO⁺(3-2) (top) and HCN(3-2) (bottom) from the B6SB dataset as observed (left), as modelled using ^3DBAROLO (middle) and the residual velocity field that results from subtracting the model from the data (right). The black arrows in the right panels indicate the position of the blue residual feature that coincides with the position of the NW hook. Velocity contour levels are drawn at [ − 75, −50, −25, 0, 25, 50, 75] km s⁻¹. The rest frame velocity is defined relative to V_sys = 441.4 km s⁻¹. Indicated on all maps are the point apertures used to extract the 1D kinematic profiles shown in Fig. 10 using corresponding symbols in white. The synthesised beam sizes are drawn in the bottom left as filled ellipses, and the cyan cross indicates the AGN position.