Colour map of centroid velocity of the H₂ 1–0 S(1) line resulting from a one-component Gaussian fit to each individual spectrum, and corrected for uneven slit illumination. Only spaxels with S/N > 5 are shown. The cross marks the position of the star. Contours of S/N = 5, 10, 15, 25, 35, 45 are superimposed in black ; the fitting error due to noise is 1σ ≃ (40/S/N) km s^-1 (see text and Sect. 2).