The core helium flash revisited: II. Two and three-dimensional hydrodynamic simulations

Abstract

We study turbulent convection during the core helium flash close to its peak by comparing the results of two and three-dimensional hydrodynamic simulations. We use a multidimensional Eulerian hydrodynamics code based on state-of-the-art numerical techniques to simulate the evolution of the helium core of a $1.25M_{\odot }$ Pop I star. Our three-dimensional hydrodynamic simulations of the evolution of a star during the peak of the core helium flash do not show any explosive behavior. The convective flow patterns developing in the three-dimensional models are structurally different from those of the corresponding two-dimensional models, and the typical convective velocities are smaller than those found in their two-dimensional counterparts. Three-dimensional models also tend to agree better with the predictions of mixing length theory. Our hydrodynamic simulations show the presence of turbulent entrainment that results in a growth of the convection zone on a dynamic time scale. Contrary to mixing length theory, the outer part of the convection zone is characterized by a sub-adiabatic temperature gradient.

19 pages, 18 figures

References in corpus (11)

• Turbulent Convection in Stellar Interiors. I. Hydrodynamic Simulation
• Active Carbon and Oxygen Shell Burning Hydrodynamics
• 3D Numerical Experimentation on the Core Helium Flash of low-mass Red Giants
• First full evolutionary computation of the He-flash induced mixing in Population II stars
• Anelastic and Compressible Simulations of Stellar Oxygen Burning
• Hydrodynamic simulations of He-shell flash convection
• Origin of the early-type R stars: a binary-merger solution to a century-old problem?
• Models for extremely metal-poor halo stars
• The core helium flash revisited: I. One and two-dimensional hydrodynamic simulations
• Nuclear burning and mixing in the first stars: entrainment at a convective boundary using the PPB advection scheme
• Structural and Nucleosynthetic Evolution of Metal-poor and Metal-free Low and Intermediate Mass Stars

Cited by in corpus (45)

• Modules for Experiments in Stellar Astrophysics (MESA)
• Hot subluminous stars
• Preparing for an Explosion: Hydrodynamic Instabilities and Turbulence in Presupernovae
• Towards Realistic Progenitors of Core-Collapse Supernovae
• Hydrodynamics of core-collapse supernovae and their progenitors
• The Last Minutes of Oxygen Shell Burning in a Massive Star
• Solar structure and evolution
• H ingestion into He-burning convection zones in super-AGB stellar models as a potential site for intermediate neutron-density nucleosynthesis
• 3D hydrodynamical simulations of a proton ingestion episode in a low-metallicity asymptotic giant branch star
• Toward a consistent use of overshooting parametrizations in 1D stellar evolution codes
• Towards a new generation of multi-dimensional stellar evolution models: development of an implicit hydrodynamic code
• Acoustic Signatures of the Helium Core Flash
• The chemical composition of carbon stars: The R-type stars
• New Evidence for Mass Loss from delta Cephei from HI 21-cm Line Observations
• When binaries keep track of recent nucleosynthesis: The Zr - Nb pair in extrinsic stars as an s-process diagnostic
• Shock-heating of stellar envelopes: A possible common mechanism at the origin of explosions and eruptions in massive stars
• Toward connecting core-collapse supernova theory with observations: I. Shock revival in a 15 Msun blue supergiant progenitor with SN 1987A energetics
• Convective boundary mixing in main-sequence stars: theory and empirical constraints
• The core helium flash revisited III. From Pop I to Pop III stars
• Impact of helium diffusion and helium-flash-induced carbon production on gravity-mode pulsations in subdwarf B stars
• Calibrating Core Overshooting Parameters With Two-dimensional Hydrodynamical Simulations
• Turbulent Mixing and Nuclear Burning in Stellar Interiors
• An Atlas of Convection in Main-Sequence Stars
• Some Stars are Totally Metal: A New Mechanism Driving Dust Across Star-Forming Clouds, and Consequences for Planets, Stars, and Galaxies
• Pulsational instabilities driven by the $\epsilon$ mechanism in hot pre-horizontal branch stars I. The Hot-Flasher Scenario
• On the challenging variability of LS IV-14°116: pulsational instabilities excited by the ε-mechanism
• Multidimensional hydrodynamic simulations of the hydrogen injection flash
• Asteroseismology and interferometry of the red giant star epsilon Oph
• Realistic 3D hydrodynamics simulations find significant turbulent entrainment in massive stars
• Impact of Convective Boundary Mixing on the TP-AGB
• Numerical approaches for multidimensional simulations of stellar explosions
• Weakly non-Boussinesq convection in a gaseous spherical shell
• Linking 1D Evolutionary to 3D Hydrodynamical Simulations of Massive Stars
• Presupernova Structure of Massive Stars
• Flare-less long Gamma-ray Bursts and the properties of their massive star progenitors
• A well-balanced scheme for the simulation tool-kit A-MaZe: implementation, tests, and first applications to stellar structure
• Seismic characterization of red giants going through the Helium-core flash
• Recent Advances in Modeling Stellar Interiors
• Hydrodynamic simulations of shell convection in stellar cores
• Multiple stellar populations and their influence on blue stragglers
• Rapid expansion of red giant stars during core helium flash by waves propagation to the envelope and implications to exoplanets
• Neutrinos and Asteroseismology of Stars over the Helium Flash
• Asteroseismic Constraints on the Models of Hot B Subdwarfs: Convective Helium-Burning Cores
• Detection horizon for the neutrino burst from the stellar helium flash
• The onset of low Prandtl number thermal convection in thin spherical shells