ExoMol line lists XXV: A hot line list for silicon sulphide, SiS

TL;DR

This paper presents comprehensive, accurate rotation-vibrational line lists and partition functions for 12 isotopologues of silicon sulphide (SiS), aiding astrophysical observations and modeling of circumstellar environments.

Contribution

It provides the first extensive, spectroscopically accurate line lists for multiple SiS isotopologues using a combination of experimental data and ab initio calculations.

Findings

Line list for $^{28}$Si$^{32}$S includes 10,104 states and 91,715 transitions.

Line lists are publicly available via ExoMol and CDS databases.

Enhanced spectral data supports astrophysical research on SiS in stellar environments.

Abstract

SiS has long been observed in the circumstellar medium of the carbon-rich star IRC+10216 CW Leo. Comprehensive and accurate rotation-vibrational line lists and partition functions are computed for 12 isotopologues of silicon sulphide ($^{28}$Si$^{32}$S, $^{28}$Si$^{34}$S, $^{29}$Si$^{32}$S, $^{28}$Si$^{33}$S, $^{30}$Si$^{32}$S, $^{29}$Si$^{34}$S, $^{30}$Si$^{34}$S, $^{28}$Si$^{36}$S, $^{29}$Si$^{33}$S, $^{29}$Si$^{36}$S, $^{30}$Si$^{33}$S, $^{30}$Si$^{36}$S) in its ground (X $^1\Sigma^+$) electronic state. The calculations employ an existing spectroscopically accurate potential energy curve (PEC) derived from experimental measurements and a newly-computed ab initio dipole moment curve (DMC). The $^{28}$Si$^{32}$S line list includes 10104 states and 91715 transitions. These line lists are available from the ExoMol website www.exomol.com and the CDS database.