Simultaneous observations of the OH maser at 1665 and 1667 MHZ in ON2

Abstract

Using Nancay radio telescope in Paris-Meudon Observatory the OH masers fromON2 have been observed. The observations were made at both frequencies of1665 and 1667 MHz, and both left and right circular polarizations, and onthe central position, respectively. The observational results indicate that the physical conditions in the central part are very different. Using a new model, i.e. the distinct multiple rotating and expanding disc-ring of OH maser,the peaks of spectra have been explained. The position parameters of the OHmaser spots corresponding to the peaks in the spectral profiles have beenobtained. Our fitting and computational results indicate that the differentpeaks are superposed by the maser spot radiation at different point indifferent disc-ring with different radii. Because the mentioned differencesare caused by the physical conditions of the OH maser formingregions, using the differences, we can study the physical characters of the OH maser forming regions of ON2.