Flux maps extracted by collapsing the channels in the range [v < −350 km s⁻¹] (blue tail; left panel), and [v > 350 km s⁻¹] (red tail; right panel). The images are extracted from the natural flux maps to maximise the sensitivity to detect faint features. The cyan contours represent the sigma levels: −1, −2, −3 (dashed) 1, 2, 2.5, and 3 (solid; 1σ ~ 0.02 Jy km s⁻¹). The black contours at 3, 4, 5, 7, and 9σ indicate the dust continuum emission (from Fig. 1). The beam ellipse is drawn in the lower right corner in both panels. The colour wedge gives the flux intensity scale in Jy km s⁻¹ beam⁻¹.