Implications of low-energy fusion hindrance on stellar burning and nucleosynthesis
- Department of Nuclear Physics, Research School of Physical Sciences and Engineering, Australian National University, Canberra, ACT 0200 (Australia) and Joint Institute for Nuclear Astrophysics, University of Notre Dame, Notre Dame, Indiana 46556 (United States)
We investigate the consequences of a new phenomenological model prediction of strongly reduced low-energy astrophysical S-factors for carbon and oxygen fusion reactions on stellar burning and nucleosynthesis. The new model drastically reduces the reaction rates in stellar matter at temperatures T< or approx. (3-10)x10{sup 8} K, especially at densities {rho} > or approx. 10{sup 9} g cm{sup -3}, in a strongly screened or even pycnonuclear burning regime. We show that these modifications change the abundance of many isotopes in massive late-type stars and in particular strongly enhance the abundances of long-lived radioactive isotopes such as {sup 26}Al and {sup 60}Fe. The reduced reaction rates also significantly complicate carbon ignition (shift carbon ignition to higher temperatures and densities) in massive accreting white dwarfs exploding as type Ia supernovae and in accreting neutron stars producing superbursts. This would require much higher ignition densities for white dwarf supernovae and would widen the gulf between theoretical and inferred ignition depths for superbursts.
- OSTI ID:
- 21064383
- Journal Information:
- Physical Review. C, Nuclear Physics, Vol. 76, Issue 3; Other Information: DOI: 10.1103/PhysRevC.76.035802; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2813
- Country of Publication:
- United States
- Language:
- English
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