Back to Volume
Paper: VLBA Imaging of 12.2 GHz Methanol Masers
Volume: 144, Radio Emission from Galactic and Extragalactic Compact Sources, IAU Colloquium 164
Page: 375
Authors: Ellingsen, S. P.; McCulloch, P. M.; Diamond, P. J.; Norris, R. P.
Abstract: We have used the VLBA to image the 12.2 GHz (\transe\/) masing transition of methanol toward the massive star formation region G345.01+1.79. The maser spots are distributed in a curved structure with a near monotonic velocity distribution along the curve. The cluster of maser emission covers an area of approximately 200 milli-arcseconds in right ascension and 70 milli-arcseconds in declination. Comparison of the positions of the 12.2 GHz methanol maser spots in G345.01+1.79 as determined from the 1995 VLBA observations with 1988 Parkes-Tidbinbilla Interferometer observations shows that the relative positions of the maser spots detected in both epochs has changed by less than 5 milli-arcseconds during that interval. Assuming a distance of 2.3 kpc to G345.01+1.79 implies an upper limit on the relative tangential velocities of the maser spots of 7 km/s.
Back to Volume