An experimental approach to the prediction of complete millimeter/submillimeter spectra at astrophysical temperatures: applications to confusion limited astrophysical observations

Ohio State University, The, Columbus OH

Investigators

Abstract

Dr. de Lucia and his team address the problem of the large incompleteness of millimeter and submillimeter (mm/submm) astrophysical catalogs. Theoretical work and laboratory spectra are needed to make optimal analysis of the data from ALMA and other mm/submm observatories. The work here aims to complete the spectroscopic survey of 8 "weed" molecules in the ALMA early science bands and to develop a database that will reduce the number of unidentifiable lines in astronomical spectral surveys. It is a continuation of previous work that is based on analyses of about 1000 intensity calibrated mm/submm spectra taken over a range of temperatures for each molecule. The accuracy of the results is validated by studying eight major interstellar weeds. The previous results revealed the incompleteness is the astrophysical data base and the researchers provided theoretical explanations to show the incompleteness as a function of source temperature. The objectives of this work are to develop a new approach for the characterization of mm/submm molecular spectra. Characterization of the complete spectra is done through analysis of the measured temperature dependence of intensities, together with quantum mechanical analyses for subsets of the spectra used for reference. Including the intensity calibration of complete spectra will substantially improve spectral catalogs and help to address the astrophysical "weed and clutter" problems in millimeter and submillimeter spectroscopy. As part of this project, graduate students are trained in experimental millimeter and submillimeter spectroscopy, and in developing methods for archiving and disseminating the results.