Sky-projected maser radii, derived from the ratio of the maser l.o.s. velocity with the angular velocity (see Sect. A), versus position projected along the major axis of the spatial distribution for the maser cluster “A” (upper panel) and the combined clusters “B” + “C” (lower panel). Dot size is proportional to the logarithm of the maser intensity and vertical errorbars give the estimated errors of the maser radii. The black dashed line denotes the “Y = X” axis.