Gas temperature dependent sticking of hydrogen on cold amorphous water ice surfaces of interstellar interest

摘要

Using the King & Wells method, we present experimental data on the dependenceof the sticking of molecular hydrogen and deuterium on the beam temperatureonto non- porous amorphous solid water (ASW) ice surfaces of interstellarinterest. A statistical model that explains the isotopic effect and the beamtemperature behavior of our data is proposed. This model gives an understandingof the discrepancy between all known experimental results on the sticking ofmolecular hydrogen. Moreover it is able to fit the theoretical results of V.Buch et al. [Astrophys. J. (1991), 379, 647] on atomic hydrogen and deuterium.For astrophysical applications, an analytical formula for the stickingcoefficients of H, D, H2, D2 and HD in the case of a gas phase at thermalequilibrium is also provided at the end of the article.