Production of 14C and neutrons in red giants.
Abstract
We have examined the effects of mixing various amounts of hydrogen-rich material into the intershell convective region of red giants undergoing helium shell flashes. We find that significant amounts of C-14 can be produced via the N-14(n, p)C-14 reaction. If substantial portions of this intershell region are mixed out into the envelopes of red giants, then C-14 may be detectable in evolved stars. We find a neutron flux many orders of magnitude above the flux required for the classical s-process, and thus an intermediate neutron process (i-process) may operate in evolved red giants. In all cases studied we find substantial enhancements of O-17. These mixing models offer a plausible explanation of the observations of enhanced O-17 in the carbon star IRC 10216. For certain physical conditions we find significant enhancements of N-15 in the intershell region.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- February 1977
- DOI:
- 10.1086/155030
- Bibcode:
- 1977ApJ...212..149C
- Keywords:
-
- Carbon Stars;
- Carbon 14;
- Neutrons;
- Red Giant Stars;
- Stellar Evolution;
- Astrophysics;
- Late Stars;
- Nuclear Reactions;
- Astrophysics