Western Kentucky University
Department of Physics and Astronomy

Colloquium

Dr. Charles Poteet

Space Telescope Science Institute

"The Composition of Cosmic Dust in Interstellar and Circumstellar Environments"

October 23, 2017 @ 4:00 pm in TCCW 201

Abstract

Cosmic dust consists of microscopic particles of matter that exist in a vast range of astrophysical environments. Although once regarded as an annoying “interstellar fog”, these particles play an essential role in shaping our understanding of both the evolution of the interstellar medium and the formation of stars and planets. Precise observational constraints on the composition of cosmic dust is critical in our knowledge of the astrophysical environments in which it exists. The chemical and physical properties of these particles can be determined by observing their characteristic spectroscopic features at infrared wavelengths. Space-based observations of interstellar and circumstellar environments reveal that cosmic dust is primarily comprised of silicates, carbonaceous materials, and molecular ices. Using optimized techniques in mid-infrared spectroscopy, I will discuss our current knowledge on the composition of cosmic dust (specifically silicates and ices) and the implications it has on the star and planet formation process, as well as the elemental budget of the interstellar medium.