High-resolution, mid-infrared spectroscopy of young stellar environments

University Of California-Davis, Davis CA

Investigators

Abstract

This project will utilize the unique observational technology developed in part by Dr. Richter to advance our understanding of the origin of planets. Using the Texas Echelon-cross-Echelle Spectrograph on the Gemini North 8.-meter telescope, he will observe the material from which planets are currently believed to be forming around young stars. The results will bear on circumstellar disk parameters such as the gas temperatures, gas dispersal time, degree of radial mixing, settling and/or growth of dust grains, and gas chemical composition at planet forming radii. These observations will follow a two-pronged approach. First Dr. Richter will search for unambiguous spectral signatures of disk emission in the pure rotational spectral lines of molecular hydrogen among 25 known circumstellar disks. The resolution of the spectrograph will allow the study of the disk line profiles from which it will be possible to infer gas temperatures and warm gas masses among the best detections. These disks will be followed up with observations of other important molecules, including water, acetylene, and hydrogen cyanide. The abundances of these molecules, along with chemical models of protoplanetary disks, will provide insight into the physical processes taking part in the planet forming regions of these young stellar systems. This project will also assure continued access by the astronomical community to this unique instrument, which fills an important gap in wavelength coverage long ward of 25 microns, offers exceptional sensitivity, and has far greater spectral resolution than is possible from space in the mid-infrared. A graduate student will also be trained in instrumentation and observing on large optical telescopes. The graduate student to be supported here will also maintain, operate and improve the spectrograph as part of a Ph.D. dissertation.