The sky field around the position of B2200+420 (BL Lac), as in Fig. 2. The map of CO emission at lower left superposes the integrated intensity in the range v = 0−2 km s^-1 as red contours against a background grayscale representing emission at v  ≤  0 km s^-1. Molecular absorption and most emission is sequestered in the blue wing of the core of the HI absorption profile but a red-shifted emission component is present to the Northeast as illustrated by the spectrum at position “C” indicated at lower left.