LABORATORY AND TELESCOPE SPECTRA OF INTERSTELLAR MOLECULES

Abstract

During the past four years, we have developed a broad based program in the area of molecular radio astronomy oriented toward maximizing the efficiency and accuracy of microwave spectral line observation and identification. This effort has involved laboratory measurements, extensive spectral calculations and telescope observations. Critically evaluated spectral reviews on 13 of the more than 30 known interstellar molecules have been published in the Journal of Physical and Chemical Reference Data and work is in progress on several additional molecules. Two recently detected species, dimethyl $ether^{1}$ and trans-ethyl $alcohol,^{2}$ will be discussed in terms of the interaction of the laboratory measurements and analysis with the telescope detections. Two interstellar molecules are currently being reanalyzed for inclusion in the critical review series: acetaldehyde $(CH_{3}CHO)$ in collaboration with A. Bauder and dimethyl ether $(CH_{3}OCH_{3})$ in collaboration with H. Dreizler. In both cases new laboratory measurements have been made in order to provide the data base required for accurate predictions of spectral lines with $J \leq 12$ up to a frequency of 250 GHz. A brief description of each of these reviews will be presented in order to illustrate the format, spectral information, and utility which these spectral reviews are designed to provide.