The Detection of New Methanol Masers in the 5_{-1}-4_0E Line

Abstract

Fifty-one objects in the 5_{-1}-4_0E methanol line at 84.5 GHz were detected during a survey of Class I maser sources. Narrow maser features were found in 17 of these. Broad quasi-thermal lines were detected towards other sources. One of the objects with narrow features, the young bipolar outflow L 1157 was also observed in the 8_0-7_1A+ line at 95.2 GHz; a narrow line was detected at this frequency. Analysis showed that the broad lines are usually inverted. The quasi-thermal profiles imply that the line opacities are not larger than several units. These results confirm the plausibility of models in which compact Class I masers appear in extended sources as a result of an appropriate velocity field. Measurements of linear polarization at 84.5 GHz in 13 sources were made. No polarization was found except a tentative detection of a weak polarization in M 8E.

References in corpus (2)

• Non-equilibrium excitation of methanol in Galactic molecular clouds: multi-transitional observations at 2 mm
• Detection of a new methanol maser line with the Kitt Peak 12-m telescope by remote observing from Moscow

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