Through The Looking Glass: A Re-analysis of Silicate Dust Spectral Features

Angela Speck (University of Missouri)

Silicate dust plays an essential role in many astrophysical environments. The ?amorphous? silicate spectral features have been observed in our solar system, young stellar objects, star formation regions, novae, and the diffuse and dense interstellar medium as well as in extragalactic environments such as quasars and AGN. This dust contributes to the physical processes inherent in star formation processes, as well as to several aspects of interstellar processes such as gas heating and the formation of molecules. The discovery of this almost ubiquitous ~10um silicate feature, led to many laboratory studies of potential cosmic dust analogs attempting to determine the exact nature of this dust. New laboratory data combined with re-analysis of observational data for asymptotic giant branch (AGB) stars will be presented. Combined, these data present a challenge to the "common wisdom" on what we think we know about silicates in space.