Deuterium Fractionation in Interstellar Clouds

摘要: This paper reviews the chemical processes responsible for fractionating deuterium in interstellar molecules. I show that this process is intrinsically a low temperature phenomenon and discuss how degree of enhancement content molecules related to physical conditions, particularly abundances, molecular clouds. If significant amounts abundant species, such as CO, are frozen out on dust grains, resulting H2D+ can result its abundance being greater than H3 + at 10 K. Transfer deuteron from then lead efficient formation multiply deuterated NHD2 ND3. Fractionation also occur grain surface reactions some simple models discussed.