The best molecular line lists for astrophysical applications today require both very high precision of line positions for strong lines and very high levels of completeness. The former is required to enable, for example, molecular detection in high-resolution cross-correlation observations of exoplanets, while completeness is required for accurate modelling of spectroscopic and radiative properties across a broad frequency and temperature range.<br/><br/>Transition metal diatomics, most notably TiO and VO, are important but unusual molecular species with very strong absorptions that dominate the visible and near-IR spectroscopy of cool stars and, probably, hot Jupiter exoplanets (temperatures approximately 1500 - 3000 K). For astronomers to understand these bodies, accurate line lists - i.e. database of energy levels and intensity of transitions between these - are essential.<br/><br/>In this talk, I will discuss the current procedure for producing high-quality line lists, a hybrid approach that takes advantage of the best available data from ab initio quantum chemistry and experimental spectroscopy, specialised computer programs like MARVEL (inverts assigned transitions to energy levels), Duo (calculates rovibronic line lists for diatomics with coupled electronic states) as well as traditional model Hamiltonian band fitting parameters. Line lists for TiO, VO and ZrO will be discussed, with comparisons made to the simpler CN and NH line lists.

Astrochemistry spectral data of transition metal diatomics: Successes, challenges and future directions

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.