Channel maps at −3 km s^-1 before and after additional flagging (see text). The offsets are as in Fig. 1. The color scale ranges from 0 to 0.3 Jy beam^-1 (0 to  ~3σ) and has been chosen to highlight the striping present in the left map (original data) but not the right (flagged data). The blue contours are at 1σ in this 0.25 km s^-1 channel. The red dot at (075, 165) shows the position where the spectrum in Fig. A.2 was extracted. Sources A and B are marked in green.