Astrochemistry: Hydrodynamics, Cosmic ray induced ice chemistry, and Complex Molecules

University Of Virginia Main Campus, Charlottesville VA

Investigators

Abstract

Astrochemistry is the study of the types of molecules and their chemistry throughout the universe. Molecules in far-away regions are interesting in themselves and as probes of the physical conditions in various regions, especially regions known as dense interstellar clouds. Stars and planets form in these clouds, which are full of molecules, some quite exotic by terrestrial standards. The investigators will study the chemistry that occurs as interstellar clouds collapse and warm up. They will determine which chemical reactions are most important and simulate the changes in the chemical composition of these regions. The final products of the cloud collapse are low-mass stars, like the sun, as well as high-mass stars, which are far brighter than the sun. The synthesis of organic (carbon-containing) molecules is of special interest, since these molecules can become part of nascent planets and are often associated with life. One critical aspect of astrochemistry is the use of chemical simulations to reproduce observational studies of molecular abundances in the gas and on dust particles, and so learn about source lifetimes and physical conditions in the interstellar and circumstellar media. The chemical simulations involve the solution of so-called coupled kinetic differential equations, which yields columns, abundances, or even spectra of many molecules as functions of density, temperature, and degree of heterogeneity. Our primary interest will be to study star formation. Given current and future interferometers, emphasis will be placed on studying the dynamics and heterogeneity of sources undergoing star formation, both the low-mass and high-mass categories. In particular, three-dimensional hydrodynamics will be combined with chemical simulations with the initial goal of understanding the chemistry that occurs during the formation of protoplanetary disks in low-mass sources, and infrared dark clouds, high-mass protostellar objects (HMPOs), and hot cores in high-mass sources. A detailed understanding of the chemistry should yield much information about the details of star formation.