Hydrodynamic simulations of shell convection in stellar cores

Abstract

Shell convection driven by nuclear burning in a stellar core is a common hydrodynamic event in the evolution of many types of stars. We encounter and simulate this convection (i) in the helium core of a low-mass red giant during core helium flash leading to a dredge-down of protons across an entropy barrier, (ii) in a carbon-oxygen core of an intermediate-mass star during core carbon flash, and (iii) in the oxygen and carbon burning shell above the silicon-sulfur rich core of a massive star prior to supernova explosion. Our results, which were obtained with the hydrodynamics code HERAKLES, suggest that both entropy gradients and entropy barriers are less important for stellar structure than commonly assumed. Our simulations further reveal a new dynamic mixing process operating below the base of shell convection zones.

8 pages, 3 figures .. submitted to a proceedings of conference about "Red Giants as Probes of the Structure and Evolution of the Milky Way" which has taken place between 15-17 November 2010 in Rome

References in corpus (4)

• Convective-reactive proton-C12 combustion in Sakurai's object (V4334 Sagittarii) and implications for the evolution and yields from the first generations of stars
• First full evolutionary computation of the He-flash induced mixing in Population II stars
• The core helium flash revisited: I. One and two-dimensional hydrodynamic simulations
• The core helium flash revisited III. From Pop I to Pop III stars

Cited by in corpus (4)

• The Lunar Gravitational-wave Antenna: Mission Studies and Science Case
• Turbulent Mixing and Nuclear Burning in Stellar Interiors
• Linking 1D Evolutionary to 3D Hydrodynamical Simulations of Massive Stars
• The $i$-processes nucleosynthesis during the formation of He-rich hot-subdwarf stars