THE DISCOVERY OF METHANOL MASERS AT 107 GHZ

A new methanol maser line at 107 GHz was discovered in five galactic s ources. All of them are known Class II methanol masers. Toward Class I methanol maser sources, the 107-GHz line was found in absorption, or as rather weak quasi-thermal emission sources. The detection of these new methanol masers supports an assumption that the level population i nversion is due to overpopulation of some K ladders relative to neighb ouring ladders.