UV photolysis vs. proton bombardment ASTRONOMY AND ASTROPHYSICS

• Main Authors: P. A. Gerakines, M. H. Moore, R. L. Hudson
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2000
• Subjects: Carbonic acid
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.390.5739; http://aa.springer.de/papers/0357002/2300793.pdf

Abstract. We have the unique ability to perform ultraviolet photolysis ( ∼ 10 eV photon −1) and ion irradiation (0.8 MeV p +) in the same experimental set-up, with ices created under identical conditions. We present experiments that show the formation of carbonic acid (H2CO3) from H2O:CO2 ice mixtures exposed to either UV photons or high-energy protons. CO and CO3 were also formed in these experiments. Results show that while H2CO3 is readily formed by p + bombardment, its formation by UV photolysis is limited by the penetration of UV photons into the ice. H2CO3 production pathways are investigated. Intrinsic IR band strengths are determined for eight IR features of H2CO3. Implications for ices found in various astrophysical environments are discussed. Key words: molecular data – molecular processes – methods: laboratory – comets: general – planets and satellites: general – ISM: molecules 1.