Velocity–galactic longitude diagram of the mean brightness temperature distribution in two different ranges of galactic latitude. The upper panel shows the velocity–galactic longitude diagram for 35 ≤  b ≤  40. The dotted circumference signals the location of Feature A (see text). The lower panel shows the same diagram for the galatic latitude strip –30 ≤  b ≤  –25. The dotted ellipse marks the location of Feature B.