title: Surface science investigations of the role of CO₂ in astrophysical ices.
abstract: We have recorded reflection-absorption infrared spectroscopy (RAIRS) and temperature-programmed desorption (TPD) data for a range of CO₂-bearing model astrophysical ices adsorbed on a graphitic dust grain analogue surface. Data have been recorded for pure CO₂, for CO₂ adsorbed on top of amorphous solid water, for mixed CO₂:H₂O ices and for CO₂ adsorbed on top of a mixed CH₃OH:H₂O ice. For the TPD data, kinetic parameters for desorption have been determined, and the trapping behaviour of the CO₂ in the H₂O (CH₃OH) ice has been determined. Data of these types are important as they can be used to model desorption in a range of astrophysical environments. RAIR spectra have also shown the interaction of the CO₂ with H₂O and CH₃OH and can be used to compare with astronomical observations, allowing the accurate assignment of spectra.
authors.affiliation: Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK.
authors.forename: John L
authors.initials: JL
authors.lastname: Edridge
authors.forename: Kati
authors.initials: K
authors.lastname: Freimann
authors.forename: Daren J
authors.initials: DJ
authors.lastname: Burke
authors.forename: Wendy A
authors.initials: WA
authors.lastname: Brown
keywords: adsorption; dust grains; infrared spectroscopy; interstellar ices; temperature-programmed desorption