The 12C + 12C Reaction and the Impact on Nucleosynthesis in Massive Stars

@article{Pignatari2012The1,
  title={The 12C + 12C Reaction and the Impact on Nucleosynthesis in Massive Stars},
  author={Marco Pignatari and Raphael Hirschi and Michael Wiescher and Roberto Gallino and Michael Bennett and Mary Beard and Christopher L. Fryer and Falk Herwig and Gabriel Rockefeller and Francis X. Timmes},
  journal={The Astrophysical Journal},
  year={2012},
  volume={762},
  pages={31}
}
Despite much effort in the past decades, the C-burning reaction rate is uncertain by several orders of magnitude, and the relative strength between the different channels 12C(12C, α)20Ne, 12C(12C, p)23Na, and 12C(12C, n)23Mg is poorly determined. Additionally, in C-burning conditions a high 12C+12C rate may lead to lower central C-burning temperatures and to 13C(α, n)16O emerging as a more dominant neutron source than 22Ne(α, n)25Mg, increasing significantly the s-process production. This is… Expand
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References

SHOWING 1-10 OF 107 REFERENCES
The effect of 12C +12C rate uncertainties on the evolution and nucleosynthesis of massive stars
Over the last 40 years, the 12C +12C fusion reaction has been the subject of considerable experimental efforts to constrain uncertainties at temperatures relevant for stellar nucleosynthesis. RecentExpand
Neutron branching in the reaction 12C + 12C
Abstract The cross section for the reaction 12C(12C, n)23Mg has been measured in the energy range Ec.m. = 3.54−4.94 MeV by counting the delayed γ-rays from 23Mg decays (half-life = 11.57 sec), and aExpand
The 12C(α, γ)16O Reaction Rate and the Evolution of Stars in the Mass Range 0.8 ≤ M/M☉ ≤ 25
We discuss the influence of the 12C(α, γ)16O reaction rate on the central He burning of stars in the mass range 0.8-25 M☉, as well as its effects on the explosive yields of a 25 M☉ star of solarExpand
s-Process Nucleosynthesis in Advanced Burning Phases of Massive Stars
TLDR
It is shown that the recent compilation of the 22Ne(α,n)25Mg rate leads to a remarkable reduction of the efficiency of the s-process during core He burning, which leads to the lowest overproduction factor of 80Kr found to date duringcore He burning in massive stars. Expand
S-process nucleosynthesis in massive stars and the weak component. I. Evolution and neutron captures in a 25 solar mass star
Evolutionary calculations of a typical massive star are run in order to analyze the n-capture process occurring during the hydrostatic core He-burning phase, studying the effects of variations in theExpand
The 12C + 12C sub-coulomb fusion cross section☆
Abstract The 12 C + 12 C fusion cross section has been studied over the energy range 2.46 ≦ E c.m. ≦ 5.88 MeV. The yields of the γ-rays emitted from the first excited states of 23 Na and 20 Ne,Expand
EVOLUTION AND NUCLEOSYNTHESIS IN LOW-MASS ASYMPTOTIC GIANT BRANCH STARS. II. NEUTRON CAPTURE AND THE s-PROCESS
We present a new analysis of neutron capture occurring in low-mass asymptotic giant branch (AGB) stars suffering recurrent thermal pulses. We use dedicated evolutionary models for stars of initialExpand
THE s-PROCESS IN ROTATING ASYMPTOTIC GIANT BRANCH STARS
We model the nucleosynthesis during the thermal pulse phase of a rotating, solar metallicity, asymptotic giant branch (AGB) star of 3 M☉, which was evolved from a main-sequence model rotating withExpand
The Nucleosynthesis of 26Al and 60Fe in Solar Metallicity Stars Extending in Mass from 11 to 120 M☉: The Hydrostatic and Explosive Contributions
We present the 26Al and 60Fe yields produced by a generation of solar metallicity stars ranging in mass between 11 and 120 M☉. We discuss the production sites of these γ-ray emitters and quantify theExpand
Sensitivity of p-process nucleosynthesis to nuclear reaction rates in a 25 M. supernova model
The astrophysical p-process, which is responsible for the origin of the proton-rich stable nuclei heavier than iron, was investigated using a full nuclear reaction network for a Type II supernovaExpand
...
1
2
3
4
5
...