Presentation #412.01 in the session Laboratory Astrophysics.
The formation of some complex organics observed throughout the interstellar medium (ISM) and planetary atmospheres has been attributed to the thermal and photo-processing of ices on grains or planetary surfaces. This processing may also lead to isomerization, fractionation, or complete molecular dissociation – of which none are well-studied experimentally. Ice provides a catalytic surface for molecular formation, and once heated or irradiated, the volatile species sublimate and can then contribute to gas-phase chemistry. However, the relationship between ice and gas compositions is not well understood. To provide insight into these chemical pathways, we have developed a laboratory technique that uses gas-phase rotational spectroscopy at submillimeter/far-IR wavelengths to study sublimation products of UV-photolyzed and/or heated ice samples. With this technique, we can quantify the chemical components of complex gas mixtures including structural isomers, conformers, isotopes, and spin isomers, and the laboratory spectra can be compared directly to remote observations of the interstellar medium, comets, and other icy planetary bodies. This presentation will provide experimental details of SubLIME, the Sublimation of Laboratory Ices Millimeter/submillimeter Experiment, and recent results of low-temperature UV photolysis experiments- including studies of the ortho-to-para ratio (OPR) of formaldehyde and preliminary work on the formation of complex species from cometary ice analogs.