ИСТИНА

We explore a possible common pumping mechanism for class I methanol masers (cIMM) and the OH(1720) maser, for those cases where both masers are found near molecular outflows that might shock the interstellar gas and provide for collisional pumping of both molecular masers. The observations were carried out in 2013 toward 20 cIMM positions in EGOs, which are MYSO and outflows identified from the GLIMPSE survey by association with extended 4.5 m emission. The JVLA was used in C configuration (synthesized beam 12") in the L frequency band in four OH lines. OH maser emission was detected in 10 sources; all in main OH lines. OH(1720) emission was detected in only one EGO G45.47+0.07, the strongest at 4.5 m. In it, the separation between peak OH(1720) and OH(1665) maser features is 0.6"; between OH(1720) and cIMM is 6" (0.02 and 0.17 pc, respectively). The magnetic field strength is identified from Zeeman pairs in which the RCP and LCP components are coincident on the maps of maser spots and varies from about 0.6 to tens of mG for different objects. To check larger region around every EGO we re-observed these 10 using NRT (France) with a beam 3.5’x19’. The result for emission lines is the same, but half of the sources also show absorption at 1720 MHz. Constraints on the parameters of the bipolar outflows and physical conditions in the masering medium as well as on the type of interstellar shocks producing cIMM pumping but not OH(1720) in EGOs are discussed.