Contribution Invited Talk
Laboratory Studies of Molecular Dynamics at the Gas-Solid Interface
- Dr. Sergio IOPPOLO
- Dr. Sergio IOPPOLO (Open University)
My talk will review the most recent laboratory work performed at the Sackler Laboratory for Astrophysics (Leiden University, NL), at the Blake Research Group (Caltech, US), and at the Astrochemistry Group (Open University, UK). Laboratory experiments showed that surface reaction mechanisms on cold interstellar dust grains initiate molecular chemistry through the formation of H2, and likely dominate the formation of complex organic molecules (COMs) in space. For decades, surface complex molecule formation has been thought to be triggered largely by energetic processing. Very recently, my co-workers and I gave the first laboratory evidence that the building blocks of sugars, fats, and proteins can be formed through non-energetic induced surface reactions under dark molecular cloud conditions (Fedoseev et al. 2015). Since the identification of solid complex prebiotic molecules is difficult because of their low expected interstellar abundances and the overlap of their absorption features with those from the more abundant species in the mid-IR, COMs have been only observed in the gas phase in the sub/millimetre range. Novel laboratory THz time-domain techniques combined to THz radiometry have the potential to allow the detection of COMs in the solid phase in the interstellar medium and understand molecular dynamics and desorption mechanisms of complex species by exploring interlayer vibrational and single molecule torsional modes of ices, phonon modes in solids, and the rovibrational transitions of larger gas-phase species at the gas-solid interface.