CO(5 − 4) velocity map with the continuum superimposed (black contours, referring to the 3 and 4σ contour from Fig. 1) and with the centroids of the flux maps obtained by integrating the channels in the red (0/300 km s⁻¹) and blue (−300/0 km s⁻¹) part of the core line profile (red and blue contours, respectively; the contours are drawn at 5, 6σ and 8, 9σ, respectively). The observed shift of the centroids is ~0.1^″. The red line shows the direction of the major axis of the rotating disc.