New detections of maser and thermal SiO emission

Abstract

A sensitive search for J = 1-0, v = 1 and v = 0 SiO in a variety of stellar and interstellar sources has been performed with the 100 m telescope of the MPIfR. Numerous new detections of SiO maser emission from Mira variables, short-period variables, and OH/IR stars were made which increase the number of known SiO sources by nearly two-thirds. Strong linearly polarized velocity features were observed in the v = 1 emission of R Leo. Maser emission in the v = 0 line was seen in at least four Mira variables; thermal or quasi-thermal v = 0 emission was observed in several other sources. First detections of thermal v = 0 emission in the J = 1-0 line of SiO were made in the star forming regions W3 and NGC 7538.