Nanoscale Silicate Stardust: Astrochemical Relevance and Observational Signatures

Stefan T. Bromley, Institute of Theoretical and Computational Chemistry, University of Barcelona, Spain

Abstract

Cosmic dust is found throughout the universe. Formed around aging stars or in supernovae, nascent grains are initially thrown into harsh interstellar space where they reside for millions of years. When eventually finding denser and warmer regions of space, dust becomes the main driver for astrochemistry by providing catalytic sites for reactions while shielding against destructive high energy radiation. Cosmic dust is thereby essential for the formation of a huge range of molecules from water and hydrogen to complex organic molecules. Eventually, these denser regions of space become the birthplace for new stars with orbiting planets largely built from accretion of dust grains. This presentation shows how computational chemistry can help astronomers identify the chemical composition and structure of cosmic dust and how it contributes to fundamental astrochemical processes. The focus is on nanoscale silicate dust as this is likely to be the most common type of solid object in the universe.