OBSERVATIONS OF NON TYPICAL MASERS AT THE RT-22 RADIO TELESCOPE IN 2004–2013

Abstract

Purpose: Some peculiarities of emission of Class I methanol masers on the 80–71A+ transition at 95 GHz in sources closely associated with protostar-forming regions and in supernova remnants are studied. Here belongs the investigation of SiO (J=2–1) maser variability in R Cassiopeiaе, too. Design/methodology/approach: Search for Class I methanol masers is based on the idea of coincidence of regions of their emission with sources of OH masing transition in the bottom level of energy at frequency of 1720 MHz (2Π3/2 J=3/2 F=2–1). Findings: Two methanol masers on transition 80–71A+ (95 GHz) in the supernova remnants IC 443 and Kes 79 are detected. Variabilities of SiO maser emission on transition J=2–1 in R Cassiopeiaе are shown for the first time. Conclusions: Variability of methanol and SiO masers is their general feature. On the example of three objects, the possibility of using the 1720 MHz OH maser as an indicator in the search for Class I methanol masers is shown. Especially it is important in the study of methanol maser emission in supernova remnants that has been proved to be true by detection of methanol masers on transition 80–71A+ (95 GHz) in IC 443 and Kes 79. Features of spectra variability of emission in R Cassiopeiaе testify to formation and disappearance of SiO (J=2–1) masers.

Keywords

• maser radiation
• supernova remnants
• molecular clouds
• methanol
• sio