Gamow-Teller transitions from 24Mg and its impact on the electron capture rates in the O + Ne + Mg cores of stars

Abstract

Electron captures on nuclei play an important role in the collapse of stellar core in the stages leading to a type-II supernova. Recent observations of subluminous Type II-P supernovae (e.g. 2005cs, 2003gd, 1999br) were able to rekindle the interest in 8 - 10 which develop O+Ne+Mg cores. We used the proton-neutron quasiparticle random phase approximation (pn-QRPA) theory to calculate the B(GT) strength for 24Mg \rightarrow 24Na and its associated electron capture rates for incorporation in simulation calculations. The calculated rates, in this letter, have differences with the earlier reported shell model and Fuller, Fowler, Newman (hereafter F2N) rates. We compared Gamow-Teller strength distribution functions and found fairly good agreement with experiment and shell model. However, the GT centroid and the total GT strength, which are useful in the calculation of electron capture rates in the core of massive pre-supernova stars, lead to the enhancement of our rate up to a factor of four compared to the shell model rates at high temperatures and densities.

arXiv comment13 pages, 3 figures

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Cited by in corpus (13)

• Comparative study of Gamow-Teller strength distributions in the odd-odd nucleus 50V and its impact on electron capture rates in astrophysical environments
• Weak-interaction mediated rates on iron isotopes for presupernova evolution of massive stars
• Ground and excited states Gamow-Teller strength distributions of iron isotopes and associated capture rates for core-collapse simulations
• Neutrino energy loss rates and positron capture rates on ${}^{55}$Co for presupernova and supernova physics
• Stellar ${\beta }^{\pm }$ decay rates of iron isotopes and its implications in astrophysics
• Stellar neutrino energy loss rates due to ${}^{24}$Mg suitable for O+Ne+Mg core simulations
• Comparison of Gamow-Teller strengths in the random phase approximation
• Nuclear structure and weak rates of heavy waiting point nuclei under rp-process conditions
• Validity of Brink Axel Hypothesis for calculations of allowed stellar weak rates of heavy nuclei
• Impact of the Brink Axel Hypothesis on Unique First Forbidden \b{eta} transitions for r process nuclei
• Detailed microscopic calculation of stellar electron and positron capture rates on ${}^{24}$Mg for O+Ne+Mg core simulations
• Gamow-Teller strength distributions and stellar weak-interaction rates for ${}^{76}$Ge and ${}^{82}$Se using the deformed pn-QRPA model
• Gamma Ray Heating and Neutrino Cooling Rates due to Weak Interaction Processes on sd-shell Nuclei in Stellar Cores