An Experimental Approach to the Prediction of Complete Millimeter/Submillimeter Spectra at Astrophysical Temperatures: Applications to Confusion Limited Astrophysical Observations

Ohio State University Research Foundation -Do Not Use, Columbus OH

Investigators

Abstract

AWARD NO: AST - 0805853 INSTITUTION: Ohio State University Research Foundation PI: Frank C De Lucia TITLE: An Experimental Approach to the Prediction of Complete Millimeter/Submillimeter Spectra at Astrophysical Temperatures: Applications to Confusion Limited Astrophysical Observations ABSTRACT This project will develop and exploit a new approach to laboratory spectroscopy in the millimeter/submillimeter spectral region. It is expected to provide a path to a long sought and challenging goal: a significant reduction in the number of unidentified lines (U-lines) and a reduction in the clutter limit of millimeter and submillimeter astronomical spectra. Here, complete, intensity calibrated spectra (obtained over an appropriate range of well defined temperatures) will be used to produce direct experimental measurements of all of the line frequencies, transition strengths, and the energies of the lower states involved in each transition of molecular species of interest. These are the parameters required by the astrophysical community. Also of note, this experimental approach will reduce the analysis time required for molecules with even moderately complex spectra by a large factor. The spectroscopic science and technology that are the foundations of this project and its relation to the traditional bootstrap quantum mechanical models used in line identification will also be developed. As an example of the symbiosis of the two approaches, the experimental approach provides a complete and intensity calibrated spectrum at an arbitrary temperature, and the lower state energy and transition strength of each line. The latter are powerful pieces of information that are ordinarily not available for use in the assignment phase of the bootstrap cycle. In turn, the quantum models will provide intensity calibration to the experimental approach and a means for establishing error limits. This work is expected to have a major impact on the field of molecular astrophysics and its interdisciplinary partners, chemistry and spectroscopy. The project will therefore be carried out in collaboration with a diverse team of national and international astronomers, chemists and spectroscopists. Both a postdoctoral research associate and a graduate student will be trained in experimental/laboratory millimeter/submillimeter spectroscopy through this project.