Monte Carlo White Dwarfs


Astronomy research
  Software Infrastructure:
     My instruments
  White dwarf supernova:
     Remnant metallicities
     Colliding white dwarfs
     Merging white dwarfs
     Ignition conditions
     Metallicity effects
     Central density effects
     Detonation density effects
     Tracer particle burning
     Subsonic burning fronts
     Supersonic burning fronts
     W7 profiles
  Massive star supernova:
     Rotating progenitors
     3D evolution
     26Al & 60Fe
     44Ti, 60Co & 56Ni
     Yields of radionuclides
     Effects of 12C +12C
     SN 1987A light curve
     Constraints on Ni/Fe ratios
     An r-process
     Compact object IMF
     Neutrino HR diagram
     Pulsating white dwarfs
     Pop III with JWST
     Monte Carlo massive stars
     Neutrinos from pre-SN
     Pre-SN variations
     Monte Carlo white dwarfs
     SAGB stars
     Classical novae
     He shell convection
     Presolar grains
     He burn on neutron stars
     BBFH at 40 years
  Chemical Evolution:
     Iron Pseudocarbynes
     Radionuclides in the 2020s
     Hypatia catalog
     Zone models H to Zn
     Mixing ejecta
     γ-rays within 100 Mpc
  Thermodynamics & Networks
     Stellar EOS
     12C(α,γ)16O Rate
     Proton-rich NSE
     Reaction networks
     Bayesian reaction rates
  Verification Problems:
     Validating an astro code
Software instruments
cococubed YouTube
Bicycle adventures
Public Outreach
Education materials

AAS Journals
AAS YouTube
2020 Celebration of Margaret Burbidge
2020 Digital Infrastructure
2021 MESA Marketplace
2021 MESA Summer School
2021 ASU Solar Systems
2021 ASU Energy in Everyday Life

Contact: F.X.Timmes
my one page vitae,
full vitae,
research statement, and
teaching statement.
Properties Of Carbon-Oxygen White Dwarfs From Monte Carlo Stellar Models (2016)

In this article 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 $\Delta {\rm M}_{{\rm 1TP}} \simeq 0.019 \, {\rm M}_{\odot}$ for the core mass at the first thermal pulse, $\Delta t_{{\rm 1TP}} \simeq$ 12.50 Myr for the age, $\Delta \log(T_c/K) \simeq$ 0.013 for the central temperature, $\Delta \log(\rho_c / {\rm g \ cm^{-3}}) \simeq$ 0.060 for the central density, $\Delta Y_{{\rm e,c}} \simeq$ 2.6×10-5 for the central electron fraction, $\Delta X_c (^{22}{\rm Ne}) \simeq$ 5.8×10-4, $\Delta X_c(^{12}{\rm C}) \simeq$ 0.392, and $\Delta X_c(^{16}{\rm O}) \simeq$ 0.392. Uncertainties in the experimental $^{12}{\rm C}(\alpha,\gamma)^{16}{\rm O}$, triple-$\alpha$, and $^{14}{\rm N}(p,\gamma)^{15}{\rm O}$ 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.

image image
image image
image image
image image