PI: Sean Brittain, University of Notre Dame, Sean.Brittain.email@example.com
Address: Department of Physics, 225 Nieuwland Science Hall, Notre Dame, IN 46556-5670, USA
CoI: Terrence W. Rettig, University of Notre Dame
CoI: Craig A. Kulesa, University of Arizona
Title: H_3^+, H_2 and CO Line Emission as a Unique Probe of the Structure of Circumstellar Disks
Abstract: Planet formation has long been known to be intimately associated with the accretion and evolution of gas and dust around disks of young stars. A comprehensive understanding of the physics and chemistry of young circumstellar disks is therefore essential to a complete picture of star and planet formation, yet basic questions about the gas content and physical processes in protoplanetary disks remain largely unanswered. Recent observations of the circumstellar disk around Herbig Ae star HD 141569 by this group have uncovered highly-excited emission lines from H_3^+ and CO which must stem from circumstellar, possibly protoplanetary material close to the young star. We propose a highly targeted spectroscopic study of three unique disk systems, that will measure the abundances and excitation mechanisms of CO, H_2 and H_3^+, thereby constraining the gas content, physical conditions and chemical photo-processing of the energetic molecular gas in these disks. Such observations represent significant and timely tests of theory and exploit the unique capabilities of the Phoenix spectrometer at Gemini South.
National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360