This project is a three-year theoretical investigation into the gas and condensation chemistry of the elements in astronomical dust forming environments, with an emphasis on evolved stars. The research is an expansion of theoretical work that Dr. Lodders carried out previously. Here, working with collaborators and students, Dr. Lodders will provide a fundamental framework for interpreting the chemical composition of the gas and condensates in stellar environments. The work is important to several areas in astrophysics and cosmochemistry as chemistry takes over as soon as physical conditions allow gas molecule and condensate formation. Systems where molecular gas and dust chemistry is important include protostellar disks (with and without planetary formation); and ejecta of evolved stars that feed dust and gas to the interstellar medium, from which new stellar and planetary systems originate. The project, which focuses on chemistry at non-solar metallicities is highly relevant to planetary formation around high metallicity stars, as well as condensation around low-metallicity stars or even in dusty galaxies at high red-shift.
The project is complementary to spectroscopic studies of the molecular dominated atmospheres and circumstellar shells of red giant stars and other ?dusty? objects. The computations to be carried out here can be used as a guide to interpret observations obtained from instruments such as the Hubble Space Telescope (HST), the Infrared Space Observatory (ISO), the Spitzer Space Telescope, the Stratospheric Observatory for Infrared Astronomy (SOFIA), and the Herschel Space Observatory. Key to the project are ongoing collaborations with observers to develop and test chemical fractionation models. The work is also complementary to the analysis of presolar grains (stardust) isolated from meteorites
The ongoing collaborations of researchers with expertise in different disciplines will enhance interdisciplinary connections between meteoritics, astrophysics, and observational astronomy as well as strengthening international networks. The project also includes the participation of undergraduate students, and will provide them with valuable research experience, helping to train the next generation of astronomers. Results will be described in scientific papers, at professional meetings, and in public lectures. Expansions of Dr. Lodder?s website are planned as part of this effort to make computational results widely available.
