Modules for Experiments in Stellar Astrophysics ( ): Convective Boundaries, Element Diffusion, and Massive Star Explosions

Abstract

Abstract We update the capabilities of the software instrument Modules for Experiments in Stellar Astrophysics ( MESA ) and enhance its ease of use and availability. Our new approach to locating convective boundaries is consistent with the physics of convection, and yields reliable values of the convective-core mass during both hydrogen- and helium-burning phases. Stars with become white dwarfs and cool to the point where the electrons are degenerate and the ions are strongly coupled, a realm now available to study with MESA due to improved treatments of element diffusion, latent heat release, and blending of equations of state. Studies of the final fates of massive stars are extended in MESA by our addition of an approximate Riemann solver that captures shocks and conserves energy to high accuracy during dynamic epochs. We also introduce a 1D capability for modeling the effects of Rayleigh–Taylor instabilities that, in combination with the coupling to a public version of the radiation transfer instrument, creates new avenues for exploring Type II supernova properties. These capabilities are exhibited with exploratory models of pair-instability supernovae, pulsational pair-instability supernovae, and the formation of stellar-mass black holes. The applicability of MESA is now widened by the capability to import multidimensional hydrodynamic models into MESA . We close by introducing software modules for handling floating point exceptions and stellar model optimization, as well as four new software tools— , -Docker, , and mesastar.org—to enhance MESA ’s education and research impact.

Keywords

Affiliated Institutions

• University of California, Berkeley US
• University of Wisconsin–Madison US
• The Netherlands Cancer Institute NL
• Arizona State University US
• Northwestern University US
• University of Liège BE
• University of California, Santa Cruz US
• Kurchatov Institute RU
• University of California, Santa Barbara US
• Institute for Theoretical and Experimental Physics RU
• The University of Tokyo JP
• Kavli Institute for the Physics and Mathematics of the Universe JP
• Lomonosov Moscow State University RU
• University of Amsterdam NL

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