Work

ExoPhoto : a data base of temperature-dependent photodissociation cross-sections

Year: 2025

Type: article

Abstract: ABSTRACT We present the ExoPhoto data base www.exomol.com/exophoto, an extension of the ExoMol data base, specifically developed to address the growing need for high-accuracy, temperature-dependent photodissociation cross-section data towards short-UV wavelengths. ExoPhoto combines theoretical models from three major computational data bases (ExoMol, ugamop and PhoMol) and experimental data sets from two experimental groups, providing extensive wavelength and temperature coverage. ExoPhoto currently includes photodissociation data for 20 molecules: $\text{AlH}$, $\text{HCl}$, $\text{HF}$, $\text{MgH}$, $\text{OH}$, $\text{NaO}$, $\text{MgO}$, $\text{O}_2$, $\text{AlCl}$, $\text{AlF}$, $\text{CS}$, $\text{HeH}^+$, $\text{CO}$, $\text{CO}_2$, $\text{H}_2\text{O}$, $\text{SO}_2$, $\text{C}_2\text{H}_2$, $\text{C}_2\text{H}_4$, $\text{H}_2\text{CO}$, and $\text{NH}_3$, derived from theoretical models and supported by experimental data from 5 data bases. ExoPhoto also includes detailed data on branching ratios and quantum yields for selected data sets. The data structure of ExoPhoto follows the ExoMol framework, with a consistent naming convention and hierarchical JSON-based organization. Photodissociation cross sections are stored in a set of .photo files which provide data as a function of wavelength with one file for each target molecule temperature. Future developments aim to include more photodissociation cross section data and to provide data for molecules in non-local thermodynamic equilibrium (non-LTE). These will expand the utility of ExoPhoto for advanced astrophysical, planetary modeling and industrial applications.

Source: RAS Techniques and Instruments

DOI: 10.1093/rasti/rzaf020