The ExoMol pressure broadening diet: H2 and He line-broadening parameters

Abstract

In a variety of astronomical objects including gas giant (exo-)planets, brown dwarfs and cool stars, molecular hydrogen and helium are the major line broadeners. However, there is currently no systematic source for these parameters, particularly at the elevated temperatures encountered in many of these objects. The ExoMol project provides comprehensive molecular line lists for exoplanet and other hot atmospheres. The ExoMol database has recently been extended to provide additional data including temperature-dependent, pressure-broadening parameters. Here we assemble H2 and He pressure-broadening datasets for the molecules H2O, NH3, SO2, CH4, PH3, HCN and H2CO using available experimental and theoretical studies.