Realistic 3D hydrodynamics simulations find significant turbulent entrainment in massive stars

Abstract

Our understanding of stellar structure and evolution coming from one-dimensional (1D) stellar models is limited by uncertainties related to multi-dimensional processes taking place in stellar interiors. 1D models, however, can now be tested and improved with the help of detailed three-dimensional (3D) hydrodynamics models, which can reproduce complex multi-dimensional processes over short timescales, thanks to the recent advances in computing resources. Among these processes, turbulent entrainment leading to mixing across convective boundaries is one of the least understood and most impactful. Here we present the results from a set of hydrodynamics simulations of the neon-burning shell in a massive star, and interpret them in the framework of the turbulent entrainment law from geophysics. Our simulations differ from previous studies in their unprecedented degree of realism in reproducing the stellar environment. Importantly, the strong entrainment found in the simulations highlights the major flaws of the current implementation of convective boundary mixing in 1D stellar models. This study therefore calls for major revisions of how convective boundaries are modelled in 1D, and in particular the implementation of entrainment in these models. This will have important implications for supernova theory, nucleosynthesis, neutron stars and black holes physics.

7 pages, 6 figures, accepted for publication in MNRAS

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Cited by in corpus (7)

• The physics of Core-Collapse Supernovae: explosion mechanism and explosive nucleosynthesis
• Convective boundary mixing in main-sequence stars: theory and empirical constraints
• 3D stellar evolution: hydrodynamic simulations of a complete burning phase in a massive star
• The Occurrence and Impact of Carbon-Oxygen Shell Mergers in Massive Stars
• Explaining the ${}^{12}\text{C}{/}^{13}\text{C}$ ratio in the Galactic halo: the contribution from shell mergers in primordial massive stars
• Convective shells in the interior of Cepheid variable stars: overshooting models based on hydrodynamic simulations
• Detailed theoretical analysis of core Helium-burning stars: Mixed mode patterns I. Impact of the He-flash discontinuity and of induced semi-convection