Ninette Abou Mrad, Fabrice Duvernay, Robin Isnard, Thierry Chiavassa, and Grégoire Danger
Astrophysical Journal 846, 124 Link to Article [https://doi.org/10.3847/1538-4357/aa7cf0]
Aix-Marseille Université, PIIM UMR-CNRS 7345, F-13397 Marseille, France

In support of space missions and spectroscopic observations, laboratory experiments on ice analogs enable a better understanding of organic matter formation and evolution in astrophysical environments. Herein, we report the monitoring of the gaseous phase of processed astrophysical ice analogs to determine if the gaseous phase can elucidate the chemical mechanisms and dominant reaction pathways occurring in the solid ice subjected to vacuum ultra-violet (VUV) irradiation at low temperature and subsequently warmed. Simple (CH₃OH), binary (H₂O:CH₃OH, CH₃OH:NH₃), and ternary ice analogs (H₂O:CH₃OH:NH₃) were VUV-processed and warmed. The evolution of volatile organic compounds in the gaseous phase shows a direct link between their relative abundances in the gaseous phase, and the radical and thermal chemistries modifying the initial ice composition. The correlation between the gaseous and solid phases may play a crucial role in deciphering the organic composition of astrophysical objects. As an example, possible solid compositions of the comet Lovejoy are suggested using the abundances of organics in its comae.