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arXiv · 1003.0938

New 9.9-GHz methanol masers

M. A. Voronkov·J. L. Caswell·S. P. Ellingsen·A. M. Sobolev
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Abstract

The Australia Telescope Compact Array (ATCA) has been used to make the first extensive search for the class I methanol masers at 9.9 GHz. In total, 48 regions of high-mass star formation were observed. In addition to masers in W33-Met (G12.80-0.19) and G343.12-0.06 (IRAS 16547-4247) which have already been reported in the literature, two new 9.9-GHz masers have been found towards G331.13-0.24 and G19.61-0.23. We have determined absolute positions (accurate to roughly a second of arc) for all the detected masers and suggest that some class I masers may be associated with shocks driven into molecular clouds by expanding HII regions. Our observations also imply that the evolutionary stage of a high-mass star forming region when the class I masers are present can outlast the stage when the class II masers at 6.7 GHz are detectable, and overlaps significantly with the stage when OH masers are active.

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M. A. Voronkov, J. L. Caswell, S. P. Ellingsen, A. M. Sobolev. 2010-03-04. New 9.9-GHz methanol masers. https://doi.org/10.1111/j.1365-2966.2010.16624.x

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