SYNTHESIS IMAGES OF 6.7 GHZ METHANOL MASERS

We have used the Australia Telescope Compact Array to produce maps in the 6.7 GHz (5(1)-6(0) A+) transition of a number of methanol masers a ssociated with star-forming regions and compared them with earlier map s of the 12.2 GHz (2(0)-3(-1) E) methanol masers. We find that in seve ral cases the 6.7 GHz and 12.2 GHz maser positions are coincident to w ithin our positional accuracy of 0.02'', placing a tight constraint on pumping mechanisms. We also find that the methanol masers are frequen tly located along fines or arcs, sometimes with velocity gradients alo ng them, and interpret this to indicate the existence of edge-on proto planetary disks around the nascent stars.