Channel maps of the 11″-resolution H I cube of NGC 1427A. For visualisation purpose we binned the channels by a factor of 5 compared to the specs given in Sect. 2, resulting in a channel width of 6.9 km s⁻¹. We use a linear grey scale from −2σ to +10σ, where σ is the noise level. The blue contour represents emission at −2σ. The black contours represent emission at 2 and 4σ. The white contours represent emission at 8, 16, 32, and 64σ. The red contours show the main features of the optical image (Fig. 1).