Fig. 1. The greyscale shows the H I column density map of UM 422, while the contours show the velocity field. The spatial resolution is 15.8" × 12.1" (1.6 kpc × 1.2 kpc). Note the presence of the small companion galaxy directly to the east of the main galaxy. Extending to the north of the companion is the beginning of a tidal feature which was first observed in the low resolution data of TBGS. Until the current high resolution data, the presence of the small companion was unknown. That this feature has a distinct kinematic major axis and rotates in the opposite sense as the larger galaxy indicates that it is a distinct galaxy

Fig. 2. H I channel maps for UM 422 and its companion. The contours plotted are -3, 3, 6, and 12 σ above the noise (1 σ = 0.6 mJy). Each channel is 5.2 km s^-1 wide, and every other channel is shown. The H I of the main galaxy and companion appear to overlap, beginning with at a velocity of 1590 km s^-1, suggesting that the two objects may be merging