Dr. Richard Freedman

December 21, 2006

“Molecular Spectroscopy, Modeling of Brown Dwarfs and Extra Solar Giant Planets”


The field of brown dwarfs and extra solar giant planets is continuing to produce new and exciting research results. The number of known extra solar giant planets continues to grow with time and new discoveries, including a recent first detection by the Spitzer Infra Red Telescope (SIRTF) of light from an extra solar giant planet. In order to make progress in understanding these objects it is necessary to construct detailed models of these objects so that their physical properties can be better understood. Dr. Freedman’s own work is related to the calculation of atomic and molecular opacities for these objects.

Using both laboratory data and theoretical calculations, the PI is developing and maintaining large molecular databases for use in the opacity calculations that are essential for the modeling of the atmospheres of these objects. He then use the results of these calculations as input to various programs that compute line by line opacities for use in the models. These opacity databases have been greatly extended as compared to the usual room temperature laboratory measurements. This is necessary as the room temperature databases have totally inadequate coverage for higher temperatures when excited levels far above the ground state become populated. The PI has used both laboratory and theoretical predictions to extend these databases, and his past experience in both laboratory and theoretical work allows him to apply the appropriate techniques to generate and prepare the data for use in his opacity programs.