Chemical pathways from atomic silicon ions to compounds of silicon

Abstract

Ions and their reactions are an integral part of the composition and chemistry of interstellar and circumstellar molecular regions. Here we report results of laboratory studies of ion chemistry which is initiated by ground-state atomic silicon ions. The results improve our understanding of interstellar molecular clouds and the molecular outflows of stars by showing how known silicon-bearing molecules may be formed, how other silicon-bearing molecules may evolve, and how gasphase ion chemistry can ultimately lead to the formation of silicon-bearing molecular aggregates such as silicon-carbide and silicate “grains”.