Catherine Walker Thesis Defense

This talk presents laboratory experiments in the service of supporting astronomical observing and development of astrochemical models. The rotational spectrum of acetaldoxime, a potential interstellar prebiotic molecule, was extended into the millimeter/sub-millimeter regime to enable astronomical searches. The rotational spectrum of acetaldoxime was extended over 70-115 and 140-700 GHz, measuring over 1700 new transitions and determining eleven new constants of its rotational Hamiltonian, in addition to the height of the barrier to internal rotation of the methyl rotor and the methyl group’s position relative to the rest of the molecule. Laboratory ice experiments were conducted using the Sublimation Laboratory Ice Millimeter/sub-millimeter Experiment at the University of Wisconsin-Madison (SubLIME-UW). These experiments explored the impact of the tuning of a source of broadband vacuum ultraviolet photons on the chemistry of photolyzed methanol ice using a combination of Fourier transform infrared spectroscopy and millimeter/sub-millimeter spectroscopy. The results presented point to a potential reason for differing results in the literature, highlighting the importance of detail and clarity in the reporting of experimental methods and helping to clarify standing questions about the applicability of laboratory experiments to astrochemical models.