Top: integrated H i  maps at a resolution of 20′′ (left) and 5′′ (right), superimposed on a HST image (from Aloisi et al. 2007). The box in the left panel shows the area covered by the right panel. The dashed line corresponds to the pseudo –1.5σ density contour. In the map at 20′′, contours are at 0.25 (dashed), 0.5, 1, 2, 4, 8, 16  ×  10²⁰ atoms cm^-2. In the map at 5′′, contours are at 3 (dashed), 6, 12, 24, 48  ×  10²⁰ atoms cm^-2. The circle shows the beam size. Middle: velocity fields at a resolution of 20′′ (left) and 5′′ (right). The box in the left panel shows the area covered by the right panel. Contours range from 722.4 to 805.6 km s^-1, with steps of 5.2 km s^-1. The circle shows the beam size. The dashed line shows the path followed to obtain the position–velocity diagram. Bottom: position–velocity diagrams at a resolution of 20′′ (left) and 5′′ (right). Contours are at  − 1.5 (dashed), 1.5, 3, 6, 12, 24  ×  σ. The box in the left panel shows the region covered by the right panel. The vertical line corresponds to the cross in the velocity fields.