12.2 GHz survey towards 6.7 GHz methanol masers

Abstract

We present results of a 12.2 GHz methanol maser survey done with the Toruń 32 m radio telescope. We examined 261 star forming-sites, known as containing 6.7 GHz maser emission sources. The survey resulted in 49 sources with maser line detection, with 21 previously unknown emissions. All detected 12.2 GHz masers have been observed at the 6.7 GHz transition. Only one 12.2 GHz source had no 6.7 GHz counterpart. We compared basic spectral line properties at both transitions. In a few cases we observed absorption features and emitting counterparts in the other monitored frequency, at the same velocity.