Spatial distribution of the PN N = 2–1 emission as a function of velocity, as observed with NOEMA, between −14 km s⁻¹ and +7.4 km s⁻¹. Each velocity channel has a width of 2 km s⁻¹. The velocity is marked in red in the top left corner of each panel. The synthesised beam is depicted by a blue ellipse in the bottom right corner. First contour and contour interval (in blue) are 3σ and 1σ of the flux distribution, respectively. The location of the shock knots B1a-B1c and B0e are marked by green crosses.