Ice in cold cosmic environments is expected to be organized in a bilayered structure of polar and apolar components. The initial water-rich layer is embedded in an icy CO envelope, which provides the feedstock for methanol formation through hydrogenation. These two components are thought to be physically segregated, unless an increase in temperature favors mobility […]
Ejection of molecules from ice-covered dust exposed to ultraviolet photons, known as photodesorption, is summoned to account for gas abundances in cold regions. Carbon monoxide (CO) is the second most abundant ice component in interstellar clouds. Photon energy transfer between CO molecules can eventually excite molecules on the ice surface, allowing desorption. CO photodesorption drops […]
The absence of complicated species from the cold gas in protoplanetary disks, and the presence of abundant CO, HCO and H2CO and negligible CH3OH, is compatible with the simulated realistic ice with X-ray. The particularly small abundances of other COMs in the cold parts of the disk are formed in the ice bulk but not […]