Efficient Formation Pathway of Methyl Formate: The Role of OH Radicals on Ice Dust

Three structural isomers of the C2H4O2 molecule, namely, methyl formate (MF; HCOOCH3), acetic acid (AA; CH3COOH), and glycol aldehyde (GA; HOCH2CHO), have attracted considerable attention as targets for understanding pathways towards molecular complexity in interstellar medium (ISM). Among these isomers, MF is decisively abundant various astronomical objects. For formation MF, surface reactions on cosmic dust would play an important role. However, when compared to observations, has been found be relatively inefficient laboratory experiments which methanol (CH3OH)-dominant ices were processed by ultraviolet (UV) photons cosmic-ray analogues. Here, we show experimental results effective photolysis CH3OH water ice at 10 K. We that key parameter leading efficient supply OH radicals H2O, significantly differs from CH3OH-rich conditions. Moreover, using ultra-high-sensitivity analysis method, succeeded constraining decisive pathway via methoxymethanol (MM; CH3OCH2OH), improve our current chemical evolution ISM.