The Deuterium Chemistry of the Early Universe
- Physics Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6372 (United States)
- W. M. Keck Laboratory for Computational Physics, Department of Physics, University of Nevada, Las Vegas, NV 89154-4002 (United States)
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
The chemistry of deuterium, as well as that of hydrogen and helium, in the postrecombination era of the expanding early universe is presented. A thorough survey of all potentially important gas-phase reactions involving the primordial elements produced in the Big Bang, with a particular emphasis on deuterium, is given. The reaction set, consisting of 144 processes, is used in a nonequilibrium chemistry model to follow the production of primordial molecules in the postrecombination era. It is found that significant deuterium fractionation occurs for HD{sup +}, HD, and H{sub 2}D{sup +}, while the abundance of D{sup +} is reduced compared to the proton abundance. Even with the enhanced fractionation of H{sub 2}D{sup +}, its abundance is predicted to be too small to cause any interesting cosmological consequences, such as possible attenuation of spatial anisotropies in the cosmic background radiation field, detections of the epochs of reionization and reheating, or constraints on the primordial deuterium abundance. HD, being the second most abundant primordial molecule after H{sub 2}, may play a role in subsequent structure formation because of its cooling radiation. {copyright} {ital {copyright} 1998.} {ital The American Astronomical Society}
- OSTI ID:
- 324911
- Journal Information:
- Astrophysical Journal, Vol. 509, Issue 1; Other Information: PBD: Dec 1998
- Country of Publication:
- United States
- Language:
- English
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