Gas-Phase Chemical and Spectral Modeling to Unlock the Diagnostic Potential of Cations in Small Body Atmospheres

This research project will computationally characterize the production and generation of the cations CO+, N2+, and CO2+ in cometary atmospheres as a proxy for the parent neutral molecules O2, N2, and CO2 which are difficult or impossible to observe from Earth. The work will thus yield new volatile diagnostics for ground-based astronomy, and the results of the project will allow astronomers to understand the role of these ions in cometary atmospheres. This project will train graduate students and early career scientists in methods of advanced computational spectroscopy and chemical modeling important in astrophysics. The investigators will characterize the production and emission mechanisms of the cations using three complementary methods. First, they will compute the electronic structure and spectroscopic constants of the cations. Second, they will use these constants and existing literature to develop a fluorescence model to predict the emission spectra of the cations in the infrared, visible, and ultraviolet wavelength regions. Finally, they will use chemical reaction networks to quantify the location and strength of the emission in cometary atmospheres. The project will also promote K-12 STEM engagement by introducing local scout groups to astronomical topics including comets, planets, and asteroids through stargazing events. 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.