Recommended Rest Frequencies for Observed Interstellar Molecular Microwave Transitions—1991 Revision

Critically evaluated transition frequencies for the molecular transitions detected in interstellar and circumstellar clouds are presented. The tabulated transitions are recommended for reference in future astronomical observations in the microwave and millimeter wavelength regions. The transition frequencies have been selected through a critical examination and analysis of the laboratory spectral data obtained from the literature. The information tabulated includes the species identity, transition frequency, uncertainty, and quantum state labels. In addition, representative line antenna temperatures are listed for a typical astronomical source for each transition as a convenience to users, and the references are cited for the laboratory and astronomical literature which have been employed.