Colloquium
Department of Physics, NCU
Laboratory Astrophysics: Non-thermal Desorption of Astrophysical Ices
Prof. Yu-Jung Chen (陳俞融)
Dept. of Physics, NCU
Date 2022.03.29 (Tue)
Place S4-625
Time 14:00-16:00
Abstract :
Ejection of molecules from ice-covered dust exposed to ultraviolet photons, known as photodesorption, is summoned to account for gas abundances in cold interstellar 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 non-thermal desorption. In this talk, we will present our studies of photon induced desorption of astrophysical ices over the past decade , and introduce you the next steps for understanding more of the mechanism of photodesorption. In the second part of this talk, we will present new and robust evidence of X-ray-induced diffusion within a realistic ice mantle at very low temperatures, leading to not only an efficient mixing of the molecular content of the ice, but also drive the desorption of species that would otherwise remain buried near the surface of dust.