An Experimental Investigation of the Synthesis of Complex Organic Molecules in Interstellar Analog Ices

This research project will investigate the formation of complex organic molecules (COMs) containing carbon, hydrogen, oxygen, and nitrogen atoms on interstellar ice. The investigators will perform laboratory experiments on ice analogs at conditions mimicking the environment of interstellar space, viz. ultra-high vacuum, low temperatures, and exposure to ultraviolet radiation. Results from the study will allow astronomers to understand how certain key COMs are formed on ices within interstellar clouds and the processes that generate molecular complexity in space. This project will provide training in advanced laboratory astrophysics to graduate and undergraduate students, including ones from groups traditionally underrepresented in STEM. The team will also give popular science lectures at local high schools, enabling educators to incorporate research into teaching and attract students to pursue STEM careers. The research team will explore the synthesis of key classes of COMs – aldehydes, ketones, carboxylic acids, esters, and amides – on interstellar ice analogs. They will do so by exposing interstellar ice analog samples to Lyman alpha radiation in a low-temperature, ultra-high vacuum space simulation chamber. The molecules produced in the experiment will be characterized in a highly complementary manner using infrared, Raman, and ultraviolet-visible spectroscopy, as well as mass spectrometry. The measurements will yield reliable reaction rates and branching fractions necessary to accurately interpret astronomical observations of COMs. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.