Generic evolution of deuterium and {sup 3}He
- Departments of Physics and Astronomy, The Ohio State University, 174 West 18th Avenue, Columbus, Ohio 43210 (United States)
- Osservatorio Astronomico di Bologna, Via Zamboni 33, I-40126 Bologna (Italy)
The primordial abundances of deuterium and of {sup 3}He, produced during big bang nucleosynthesis, depend sensitively on the baryon density. Thus, the observed abundances of D and {sup 3}He may provide useful {open_quote}{open_quote}baryometers{close_quote}{close_quote} provided the evolution from primordial to present (or, presolar nebula) abundances is understood. Inevitably, the derivation of primordial from observed abundances requires the intervention of a model for galactic evolution and, so, the inferred primordial abundances are, necessarily, model-dependent. Here, an analytic framework for the evolution of D and {sup 3}He is presented which is {open_quote}{open_quote}generic{close_quote}{close_quote} in the sense that it should describe the results of any specific galactic evolution model. The {open_quote}{open_quote}effective {sup 3}He survival fraction,{close_quote}{close_quote} {Gamma}{sub 3}, is the one free parameter which is model-specific. Solar system and interstellar data are used to infer upper and lower bounds to the primordial deuterium mass fraction ({ital X}{sub 2{ital P}}) as a function of {Gamma}{sub 3}, and these bounds are used to constrain the present baryon-to-photon ratio ({eta}) and baryon density ({Omega}{sub {ital B}}). For {Gamma}{sub 3}{ge}1/4 it is found that (from D and {sup 3}He alone): 3.1{le}{eta}{sub 10}{le}9.0; 0.045{le}{Omega}{sub {ital Bh{sup 2}}}{sub 50}{le}0.133 (where {ital H}{sub 0}=50{ital h}{sub 50} km s{sup {minus}1} Mpc{sup {minus}1}). {copyright} {ital 1995 The American Astronomical Society.}
- Research Organization:
- Univ. of Minnesota, Minneapolis, MN (United States)
- DOE Contract Number:
- FG02-94ER40823
- OSTI ID:
- 281999
- Journal Information:
- Astrophysical Journal, Vol. 453, Issue 1; Other Information: PBD: Nov 1995
- Country of Publication:
- United States
- Language:
- English
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