Photolysis of astrophysical water ice by soft x-rays and the production of h2o2 during the phases of irradiation and heating

Astrophysical water-rich ices are always exposed to ionizing radiation in space, as well as, are exposed to eventual temperature changes. In the laboratory, the studies of such ices allow us to understand their behavior and chemical changes, allowing also the quantification of important physicochemical parameters of the ice. In the present work, a sample of water ice at 12 K was irradiated by soft X-rays in the SGM beamline of LNLS/CNPEM until reaching chemical equilibrium, and then it was heated up to 220 K. Using infrared spectroscopy (IR), we mapped the chemical evolution of the sample and quantified the production of its main product, the H2O2 molecule. The study has implications for the chemistry of star-forming regions as well as cold regions of the solar system.