English

Properties of Carbon-Oxygen White Dwarfs From Monte Carlo Stellar Models

Solar and Stellar Astrophysics 2016-05-24 v1

Abstract

We investigate properties of carbon-oxygen white dwarfs with respect to the composite uncertainties in the reaction rates using the stellar evolution toolkit, Modules for Experiments in Stellar Astrophysics (MESA) and the probability density functions in the reaction rate library STARLIB. These are the first Monte Carlo stellar evolution studies that use complete stellar models. Focusing on 3 M_{\odot} models evolved from the pre main-sequence to the first thermal pulse, we survey the remnant core mass, composition, and structure properties as a function of 26 STARLIB reaction rates covering hydrogen and helium burning using a Principal Component Analysis and Spearman Rank-Order Correlation. Relative to the arithmetic mean value, we find the width of the 95\% confidence interval to be ΔM1TP\Delta M_{{\rm 1TP}} \approx 0.019 M_{\odot} for the core mass at the first thermal pulse, Δ\Deltat1TPt_{\rm{1TP}} \approx 12.50 Myr for the age, Δlog(Tc/K)\Delta \log(T_{{\rm c}}/{\rm K}) \approx 0.013 for the central temperature, Δlog(ρc/g cm3)\Delta \log(\rho_{{\rm c}}/{\rm g \ cm}^{-3}) \approx 0.060 for the central density, ΔYe,c\Delta Y_{\rm{e,c}} \approx 2.6×\times105^{-5} for the central electron fraction, ΔXc(22Ne)\Delta X_{\rm c}(^{22}\rm{Ne}) \approx 5.8×\times104^{-4}, ΔXc(12C)\Delta X_{\rm c}(^{12}\rm{C}) \approx 0.392, and ΔXc(16O)\Delta X_{\rm c}(^{16}\rm{O}) \approx 0.392. Uncertainties in the experimental 12^{12}C(α,γ)16O\alpha,\gamma)^{16}\rm{O}, triple-α\alpha, and 14^{14}N(p,γ)15Op,\gamma)^{15}\rm{O} reaction rates dominate these variations. We also consider a grid of 1 to 6 M_{\odot} models evolved from the pre main-sequence to the final white dwarf to probe the sensitivity of the initial-final mass relation to experimental uncertainties in the hydrogen and helium reaction rates.

Keywords

Cite

@article{arxiv.1603.06666,
  title  = {Properties of Carbon-Oxygen White Dwarfs From Monte Carlo Stellar Models},
  author = {C. E. Fields and R. Farmer and I. Petermann and C. Iliadis and F. X. Timmes},
  journal= {arXiv preprint arXiv:1603.06666},
  year   = {2016}
}

Comments

Accepted for publication in The Astrophysical Journal; 19 Pages, 23 Figures, 5 Tables