W. David Arnett
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View article: Shell mergers in the late stages of massive star evolution: new insight from 3D hydrodynamic simulations
Shell mergers in the late stages of massive star evolution: new insight from 3D hydrodynamic simulations Open
One-dimensional (1D) stellar evolution models are widely used across various astrophysical fields, however they are still dominated by important uncertainties that deeply affect their predictive power. Among those, the merging of independe…
View article: 3D simulations of a neon burning convective shell in a massive star
3D simulations of a neon burning convective shell in a massive star Open
The treatment of convection remains a major weakness in the modelling of stellar evolution with one-dimensional (1D) codes. The ever-increasing computing power makes now possible to simulate in three-dimensional (3D) part of a star for a f…
View article: 3D simulations of convective shell Neon-burning in a massive star
3D simulations of convective shell Neon-burning in a massive star Open
The treatment of convection remains a major weakness in the modelling of stellar evolution with one-dimensional (1D) codes. The ever increasing computing power makes now possible to simulate in 3D part of a star for a fraction of its life,…
View article: 3D stellar evolution: hydrodynamic simulations of a complete burning phase in a massive star
3D stellar evolution: hydrodynamic simulations of a complete burning phase in a massive star Open
Our knowledge of stellar evolution is driven by one-dimensional (1D) simulations. 1D models, however, are severely limited by uncertainties on the exact behaviour of many multidimensional phenomena occurring inside stars, affecting their s…
View article: 3D stellar evolution: hydrodynamic simulations of a complete burning phase in a massive star
3D stellar evolution: hydrodynamic simulations of a complete burning phase in a massive star Open
Our knowledge of stellar evolution is driven by one-dimensional (1D) simulations. 1D models, however, are severely limited by uncertainties on the exact behaviour of many multi-dimensional phenomena occurring inside stars, affecting their …
View article: Fluid dynamic mathematical aspects of supernova remnants
Fluid dynamic mathematical aspects of supernova remnants Open
Supernovae—explosions of stars—are a central problem in astrophysics since they contain information on the entire process of stellar evolution and nucleosynthesis. Rayleigh–Taylor (RT) and Richtmyer–Meshkov (RM) instabilities, developing d…
View article: Realistic 3D hydrodynamics simulations find significant turbulent entrainment in massive stars
Realistic 3D hydrodynamics simulations find significant turbulent entrainment in massive stars Open
Our understanding of stellar structure and evolution coming from one-dimensional (1D) stellar models is limited by uncertainties related to multidimensional processes taking place in stellar interiors. 1D models, however, can now be tested…
View article: Entrainment in 3D hydrodynamics simulations of neon burning
Entrainment in 3D hydrodynamics simulations of neon burning Open
Our knowledge of massive star evolution is limited by uncertainties linked with multi-dimensional processes taking place in stellar interiors. Important examples are convective boundary mixing (CBM) and entrainment, which are implemented i…
View article: 3D hydrodynamics simulations of massive stars with the PROMPI code
3D hydrodynamics simulations of massive stars with the PROMPI code Open
Evolutionary models of massive stars are affected by uncertainties related to three-dimensional processes like convection. However, it is not computationally possible to simulate at the same time both the entire lifetime of a star and its …
View article: Dynamics in a stellar convective layer and at its boundary: Comparison of five 3D hydrodynamics codes
Dynamics in a stellar convective layer and at its boundary: Comparison of five 3D hydrodynamics codes Open
Our ability to predict the structure and evolution of stars is in part limited by complex, 3D hydrodynamic processes such as convective boundary mixing. Hydrodynamic simulations help us understand the dynamics of stellar convection and con…
View article: Theoretical Studies of Accretion of Matter onto White Dwarfs and the Single Degenerate Scenario for Supernovae of Type Ia
Theoretical Studies of Accretion of Matter onto White Dwarfs and the Single Degenerate Scenario for Supernovae of Type Ia Open
We present a brief summary of the Single Degenerate Scenario for the progenitors of Type Ia Supernovae in which it is assumed that a low mass carbon-oxygen white dwarf is growing in mass as a result of accretion from a secondary star in a …
View article: Convective core entrainment in 1D main-sequence stellar models
Convective core entrainment in 1D main-sequence stellar models Open
3D hydrodynamics models of deep stellar convection exhibit turbulent entrainment at the convective-radiative boundary which follows the entrainment law, varying with boundary penetrability. We implement the entrainment law in the 1D Geneva…
View article: Relative importance of convective uncertainties in massive stars
Relative importance of convective uncertainties in massive stars Open
In this work, we investigate the impact of uncertainties due to convective boundary mixing (CBM), commonly called ‘overshoot’, namely the boundary location and the amount of mixing at the convective boundary, on stellar structure and evolu…
View article: Relative Importance of Convective Uncertainties in Massive Stars
Relative Importance of Convective Uncertainties in Massive Stars Open
In this work, we investigate the impact of uncertainties due to convective boundary mixing (CBM), commonly called `overshoot', namely the boundary location and the amount of mixing at the convective boundary, on stellar structure and evolu…
View article: Relative Importance of Convective Uncertainties in Massive Stars
Relative Importance of Convective Uncertainties in Massive Stars Open
Inlist used for the paper: "Relative Importance of Convective Uncertainties in Massive Stars" (arXiv:2006.01877) The stellar tracks and profile outputs are available on http://www.astro.keele.ac.uk/shyne/datasets/convective-boundary-mixing…
View article: Relative Importance of Convective Uncertainties in Massive Stars
Relative Importance of Convective Uncertainties in Massive Stars Open
Inlist used for the paper: "Relative Importance of Convective Uncertainties in Massive Stars" (arXiv:2006.01877) The stellar tracks and profile outputs are available on http://www.astro.keele.ac.uk/shyne/datasets/convective-boundary-mixing…
View article: Biographical Memoir of Stirling Colgate
Biographical Memoir of Stirling Colgate Open
Stirling Colgate was a remarkably imaginative physicist, an independent thinker with a wide breadth of interests and contagious enthusiasm, a born leader with enduring drive to attack fundamental problems in science. Among his many achieve…
View article: Exploring Stellar Evolution Models of sdB Stars using MESA
Exploring Stellar Evolution Models of sdB Stars using MESA Open
MESA inlists associated with Exploring Stellar Evolution Models of sdB Stars using MESA
View article: Exploring Stellar Evolution Models of sdB Stars using MESA
Exploring Stellar Evolution Models of sdB Stars using MESA Open
MESA inlists associated with Exploring Stellar Evolution Models of sdB Stars using MESA
View article: Supernova, nuclear synthesis, fluid instabilities, and interfacial mixing
Supernova, nuclear synthesis, fluid instabilities, and interfacial mixing Open
Supernovae and their remnants are a central problem in astrophysics due to their role in the stellar evolution and nuclear synthesis. A supernova’s explosion is driven by a blast wave causing the development of Rayleigh–Taylor and Richtmye…
View article: 3D Simulations and MLT: II. Onsager's Ideal Turbulence
3D Simulations and MLT: II. Onsager's Ideal Turbulence Open
We simulate stellar convection at high Reynolds number (Re$\lesssim$7000) with causal time stepping but no explicit viscosity. We use the 3D Euler equations with shock capturing (Colella & Woodward 1984). Anomalous dissipation of turbulent…
View article: 3D simulations and MLT: II. RA-ILES results
3D simulations and MLT: II. RA-ILES results Open
Extending (\citealt{alvio1}), we analyze the physics of the turbulent cascade in stars. Our simulations give an asymptotic limit for the global damping length for turbulent kinetic energy, $\ld \sim \langle u^3 \rangle /\langle \epsilon \r…
View article: Turbulent mixing and nuclear burning in stellar interiors
Turbulent mixing and nuclear burning in stellar interiors Open
The turbulent burning of nuclei is a common phenomenon in the evolution of\nstars. Here we examine a challenging case: the merging of the neon and oxygen\nburning shells in a 23 M$_{\\odot}$ star. A previously unknown quasi-steady\nstate i…
View article: Pre-nebular Light Curves of SNe I
Pre-nebular Light Curves of SNe I Open
We compare analytic predictions of supernova light curves with recent high-quality data from SN2011fe (Ia), KSN2011b (Ia), and the Palomar Transient Factory and the La Silla-QUEST variability survey (LSQ) (Ia). Because of the steady, fast …
View article: The Sirius System and Its Astrophysical Puzzles: Hubble Space Telescope and Ground-based Astrometry<sup>∗</sup>
The Sirius System and Its Astrophysical Puzzles: Hubble Space Telescope and Ground-based Astrometry<sup>∗</sup> Open
Sirius, the seventh-nearest stellar system, is a visual binary containing the metallic-line A1 V star Sirius A, the brightest star in the sky, orbited in a 50.13 year period by Sirius B, the brightest and nearest white dwarf (WD). Using im…
View article: Synergies between Asteroseismology and Three-dimensional Simulations of Stellar Turbulence
Synergies between Asteroseismology and Three-dimensional Simulations of Stellar Turbulence Open
Turbulent mixing of chemical elements by convection has fundamental effects on the evolution of stars. The standard algorithm at present, mixing-length theory (MLT), is intrinsically local, and must be supplemented by extensions with adjus…
View article: Asteroseismic Constraints on the Models of Hot B Subdwarfs: Convective Helium-Burning Cores
Asteroseismic Constraints on the Models of Hot B Subdwarfs: Convective Helium-Burning Cores Open
\nAsteroseismology of non-radial pulsations in Hot B Subdwarfs (sdB stars) offers a unique view into the interior of core-helium-burning stars. Ground-based and space-borne high precision light curves allow for the analysis of pressure and…
View article: Pre-nebular light curves of type I supernovae
Pre-nebular light curves of type I supernovae Open
We compare analytic predictions of supernova light curves with recent high quality data from SN2011fe (Ia), from KSN2011b (Ia), and the Palomar Transient Factory (PTF) and the La Silla-QUEST variability survey (LSQ) (Ia). Because of the st…
View article: Key issues review: numerical studies of turbulence in stars
Key issues review: numerical studies of turbulence in stars Open
Three major problems of single-star astrophysics are convection, magnetic fields and rotation. Numerical simulations of convection in stars now have sufficient resolution to be truly turbulent, with effective Reynolds numbers of [Formula: …