A high-resolution line list for AlO

TL;DR

This paper improves the spectroscopic line list for aluminium monoxide (AlO) using high-resolution laboratory data, aiding atmospheric detection in exoplanets through more accurate spectral models.

Contribution

The study provides a highly accurate, empirically validated line list for AlO and its isotopologues, enhancing detection capabilities in exoplanet atmospheres.

Findings

Validated 22,473 transitions for $^{27}$Al$^{16}$O

Produced an improved, spectroscopically accurate line list

Enhanced accuracy for isotopologues $^{26}$Al$^{16}$O, $^{27}$Al$^{17}$O, and $^{27}$Al$^{18}$O

Abstract

Indications of aluminium monoxide in atmospheres of exoplanets are being reported. Studies using high-resolution spectroscopy should allow a strong detection but require high accuracy laboratory data. A \textsc{marvel} (measured active rotational-vibrational energy levels) analysis is performed for the available spectroscopic data on $^{27}$Al$^{16}$O: 22\,473 validated transitions are used to determine 6\,485 distinct energy levels. These empirical energy levels are used to provide an improved, spectroscopically accurate version of the ExoMol ATP line list for $^{27}$Al$^{16}$O; at the same time the accuracy of the line lists for the isotopically-substituted species $^{26}$Al$^{16}$O, $^{27}$Al$^{17}$O and $^{27}$Al$^{18}$O are improved by correcting levels in line with the corrections used for $^{27}$Al$^{16}$O. These line lists are available from the ExoMol database at http://www.exomol.com.