Several processes have been suggested as ways of returning accreted grain mantles to the gas, thus preventing the total removal of molecules from the gas phase in dark quiescent clouds. We attempt to distinguish between them by considering not only the calculated gas-phase abundances, but also the ratio of the abundances of deuterated species to non-deuterated species. We find that the D/H ratio in molecules is relatively model-independent, but that desorption due to the formation of H-2 on grains gives the best overall agreement with the observations.
|Number of pages||7|
|Journal||Monthly Notices of the Royal Astronomical Society|
|Publication status||Published - 01 Aug 1998|
ASJC Scopus subject areas
- Space and Planetary Science