Drs. Thaddeus and Gottlieb will continue a program of laboratory and radio astronomical research on reactive molecules in the interstellar gas and in circumstellar shells. The research will emphasize Fourier Transform Microwave (FTM) spectroscopy and radio astronomical identifications of molecular ions and highly reactive neutral organic molecules. The FTM technique is the ideal means for establishing the existence of new molecules in the laboratory and for determining their abundances. It will provide crucial data for an independent search in the laboratory for the carriers of the diffuse interstellar bands. Their goal is to measure radio line frequencies of both neutral species, and also of negative and positive ions, to guide radio astronomical observations of the diffuse gas. Their determination of structures in key ions will allow the assessment of specific ion-molecule reactions in dense clouds, and provide important information on the overall chemical scheme in translucent clouds, elucidating the link between diffuse and dense interstellar clouds. They will also continue work toward increasing the sensitivity of the spectrometer.
