Absorption spectra of PS in the ultraviolet and infrared region

Spectrochim Acta A Mol Biomol Spectrosc. 2025 Jan 6:330:125704. doi: 10.1016/j.saa.2025.125704. Online ahead of print.

Abstract

The line list is essential for accurately modeling various astrophysical phenomena, such as stellar photospheres and atmospheres of extrasolar planets. This paper introduces a new line database for the PS molecule spanning from the ultraviolet to the infrared regions, covering wavenumbers up to 45000 cm-1 and containing over ten million transitions between 150,458 states with total angular momentum J < 160. Accurate line intensities for rotational, vibrational and electronic transitions are generated by using the general purpose variational code DUO. Before applying the DUO program, the potential energy curves (PECs), the electric dipole transition moments (EDTMs) and the spin-orbit coupling (SOC) matrix need to be provided, which are computed by an ab initio method at the icMRCI level. The DUO program is executed to generate two files - a state file and a transition file, which are provided to the ExoCross program which supply cross sections, intensities, partition functions, lifetimes and quantum number assignments. The cross-sections and intensities for the observed transitions are necessary for the correct modeling of the spectra. Tests of the line lists show that our predictions not only provide a favorable comparison with the experimental spectrum but also a cornerstone for various astronomical observations.

Keywords: Brown dwarfs; Molecular data; Opacity; Stars; Stellar atmosphere.