“Interstellar N-Heterocycles, Large Polycyclic Aromatic Hydrocarbons (PAHs)and PAH Clusters as Potential Boimarkers and Cosmic Biogenic Feedstock”
The purpose of this research is to investigate the formation and distribution of Aromatic Nitrogen Heterocyclic molecules (ANHs), large polycyclic aromatic hydrocarbons (LPAHs), LPAH clusters, and nanoparticles in the interstellar environment. We will also trace potential chemical modifications upon their inclusion in interstellar ices and the icy materials of developing planetary systems. The ultimate goal of this project is to determine whether interstellar ANH and other related aromatic structures, which are prevalent in our own biochemistry, might indicate an exogenous origin of life.Since tons of organic molecules come to earth every day from space, and this mass may have been a million times more on the prebiotic Earth, such molecules might have aided in making the Earth habitable, perhaps even jump-starting life. By extension, such a delivery process may be generally applicable to habitability of the planets of other stellar systems, and thus is of fundamental interest to our studies of the origins of life in the universe. This project will focus on measuring the infrared (IR) spectra of ANHs, ANH ions, LPAHs, LPAH clusters and nanoparticles under astrophysically relevant conditions; assess their relative stability under UV irradiation; analyze the UV-mediated photochemistry of these species frozen in H2O-dominated ices to determine the relevance of such chemical processes to the interstellar production of biogenically significant compounds. Since nitrogen-containing heterocycles are so important to our biochemistry, particular emphasis will be placed on ANH compounds. However this project is not limited to solely experimental work. In addition to the proposed work, we are actively pursuing related observational and theoretical projects through collaborations with other scientists at NASA, universities, and non-profits.