Velocity maps of AzTEC-3 showing [C II] emission across the velocity range of the line. The velocity range is provided at the top of the images. The gray contours are at 10, 20, 30, 40, 50, and 60σ levels from the moment-0 map of AzTEC-3, which is shown in Fig. 7. The black ellipses indicate the positions and sizes of the three companions from CASA’s IMFIT routine where the dashed ellipse around Gal-SW denotes an upper-limit point source. The “gas-bridge” structure between AzTEC-3 and Gal-S is seen in the velocity range of −584 to −358 km s⁻¹. The size of the synthesized beam is shown in the bottom left corner of the images.