ChJAA Vol 2, No 1 (2002) / Liu

A Possible Pumping Mechanism for Interstellar Class II 107 GHz Methanol Masers

Han-Ping Liu, Jin Sun


It is recognized that the interstellar methanol-107 GHz masers and OH-4.765 GHz masers towards Class II sources are associated with each other and coexist towards ultracompact HII regions. Therefore we suggest a new pumping mechanism -- methanol masers without population inversion. It can explain the formation of 107 GHz methanol masers, with the 4.765 GHz OH masers acting as a driving coherent microwave field. It is argued that this mechanism is compatible with the astronomical conditions.


H II regions --- masers --- radiation mechanisms: non-thermal --- ISM: molecules --- line: formation

Full Text:



  • There are currently no refbacks.