OH RADICAL MICROWAVE TRANSITIONS OF INTEREST IN RADIO ASTRONOMY

This abstract presents the results of one phase of research carried out at the Jet Propulsion Laboratory, California Institute of Technology, under Contract No. NAS 7-100, sponsored by the National Aeronautics and Space Administration.Author Institution: Physics Section, Jet Propulsion Laboratory, California Institute of Technology; Chemistry Department, University of Southern CaliforniaThe OH free radical transitions between 8.2 and 40 GHz have been measured, including several new transitions. Using the Van Vleck (lambda doubling) and the corrected Frosch and Foley (nuclear hyperfine splitting) Hamiltonians, a new set of molecular constants have been determined. The frequencies predicted by these constants give excellent agreement with the observed transitions. Two digital computer programs were written for this analysis. One program treats the complete OH problem, including the lambda doubling, nuclear hyperfine splittings and Stark effects. The second program uses least squares analysis methods. A rich OH spectrum is predicted below 120 GHz. The new laboratory observed transitions confirm this analysis. Intensities and Einstein A coefficients have also been calculated for all transitions. A number of the predicted low frequency microwave transitions are of interest for radio astronomy