Continuum emission associated with 6.7-GHz methanol masers

Abstract

We have used the Australia Telescope Compact Array (ATCA) to search for continuum emission toward three strong 6.7-GHz methanol maser sources. For two of the sources, G 339.88 - 1.26 and NGC 6334F (G 351.42 + 0.64), we detect continuum emission closely associated with the methanol masers. A further three clusters of masers show no radio continuum emission above our sensitivity limit of 1-5 mJy. We find the position of the 6.7-GHz methanol masers in G 339.88 - 1.26 to be consistent with the hypothesis that the masers lie in the circumstellar disc surrounding a massive star. We also argue that one of the clusters of methanol masers in NGC 6334F provides indirect observational support for the circumstellar disc hypothesis.