Castro: A New Compressible Astrophysical Solver. I. Hydrodynamics and Self-Gravity

Almgren, Ann S.; Beckner, Vince; Bell, John B.; Day, Marc; Howell, Louis H.; Joggerst, Candace C.; Lijewski, Michael J.; Nonaka, A.; Singer, Michael; Zingale, M.

doi:10.1088/0004-637x/715/2/1221

Cited by 264 publications

(277 citation statements)

References 42 publications

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“…This could also account for the differences in the heating rates, advection time to heating time ratios, gain region masses and energies, and other radiationhydrodynamic quantities discussed earlier that are more favorable for producing explosions in the CHIMERA simulations than in those of PROMETHEUS-VERTEX. Dolence et al (2015) have evolved the same four Woosley & Heger (2007) progenitors examined in this paper to ∼600 ms after bounce in axisymmetry using the CASTRO code (Almgren et al 2010;Zhang et al 2011Zhang et al , 2013 and did not obtain any explosions. CASTRO is quite distinct in that it has multidimensional, rather than RbR, MGFLD, but neglects GR and the energy coupling between neutrino energy groups (i.e., inelastic scattering), both of which improve the prospects for an explosion (Lentz et al 2012b;Müller et al 2012b).…”

Section: Other Axisymmetric Simulationsmentioning

confidence: 76%

The Development of Explosions in Axisymmetric Ab Initio Core-Collapse Supernova Simulations of 12–25 Stars

Bruenn

Lentz

Hix

et al. 2016

ApJ

204

300

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We present four ab initio axisymmetric core-collapse supernova simulations initiated from 12, 15, 20, and 25 M  zero-age main sequence progenitors. All of the simulations yield explosions and havebeen evolved for at least 1.2 s after core bounce and 1 s after material first becomes unbound. These simulations were computed with our CHIMERA code employing RbR spectral neutrino transport, special and general relativistic transport effects, and state-of-the-art neutrino interactions. Continuing the evolution beyond 1 s after core bounce allows the explosions to develop more fully and the processes involved in powering the explosions to become more clearly evident. We compute explosion energy estimates, including the negative gravitational binding energy of the stellar envelope outside the expanding shock, of 0.34, 0.88, 0.38, and 0.70 Bethe (B≡10 51 erg) and increasing at 0.03, 0.15, 0.19, and 0.52 B s 1 -, respectively, for the 12, 15, 20, and 25 M  models at the endpoint of this report. We examine the growth of the explosion energy in our models through detailed analyses of the energy sources and flows. We discuss how the explosion energies may be subject to stochastic variations as exemplfied by the effect of the explosion geometry of the 20 M  model in reducing its explosion energy. We compute the proto-neutron star masses and kick velocities. We compare our results for the explosion energies and ejected Ni 56 masses against some observational standards despite the large error bars in both models and observations.

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Section: Other Axisymmetric Simulationsmentioning

confidence: 76%

The Development of Explosions in Axisymmetric Ab Initio Core-Collapse Supernova Simulations of 12–25 Stars

Bruenn

Lentz

Hix

et al. 2016

ApJ

204

300

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“…It is therefore important to be aware of the behavior of the code in such circumstances. The behavior of CASTRO for many standard hydrodynamics test problems was detailed in the original code paper (Almgren et al 2010), and in the interest of brevity we do not repeat them all here. Instead, we focus on a subset of problems that highlight the special difficulties introduced in merger simulations.…”

Section: Numerical Test Problemsmentioning

confidence: 99%

“…This research was supported by NSF award AST-1211563. (Almgren et al (2010), https://github. com/BoxLib-Codes/Castro), wdmerger (https://github.com/ BoxLib-Codes/wdmerger), GCC (https://gcc.gnu.org/), python (https://www.python.org/), matplotlib (Hunter (2007), http://matplotlib.org/), yt (Turk et al (2011), http://yt-project.org/)…”

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confidence: 99%

White Dwarf Mergers on Adaptive Meshes. I. Methodology and Code Verification

Katz

Zingale

Calder

et al. 2016

ApJ

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The Type Ia supernova (SN Ia) progenitor problem is one of the most perplexing and exciting problems in astrophysics, requiring detailed numerical modeling to complement observations of these explosions. One possible progenitor that has merited recent theoretical attention is the white dwarf (WD) merger scenario, which has the potential to naturally explain many of the observed characteristics of SNe Ia. To date there have been relatively few self-consistent simulations of merging WD systems using mesh-based hydrodynamics. This is the first paper in a series describing simulations of these systems using a hydrodynamics code with adaptive mesh refinement. In this paper we describe our numerical methodology and discuss our implementation in the compressible hydrodynamics code CASTRO, which solves the Euler equations, and the Poisson equation for self-gravity, and couples the gravitational and rotation forces to the hydrodynamics. Standard techniques for coupling gravitation and rotation forces to the hydrodynamics do not adequately conserve the total energy of the system for our problem, but recent advances in the literature allow progress and we discuss our implementation here. We present a set of test problems demonstrating the extent to which our software sufficiently models a system where large amounts of mass are advected on the computational domain over long timescales. Future papers in this series will describe our treatment of the initial conditions of these systems and will examine the early phases of the merger to determine its viability for triggering a thermonuclear detonation.

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“…The CASTRO code (Almgren et al 2010) is a multidimensional compressible hydrodynamics code that uses adaptive-mesh refinement. The code incorporates multigroup flux-limited diffusion (MGFLD) transport of radiation (Zhang et al 2013).…”

Section: Introductionmentioning

confidence: 99%

Very Low-energy Supernovae: Light Curves and Spectra of Shock Breakout

Lovegrove

Woosley

Zhang

2017

ApJ

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The brief transient emitted as a shock wave erupts through the surface of a presupernova star carries information about the stellar radius and explosion energy. Here the CASTRO code, which treats radiation transport using multigroup flux-limited diffusion, is used to simulate the light curves and spectra of shock breakout in very low-energy supernovae (VLE SNe), explosions in giant stars with final kinetic energy much less than 10 51 erg. VLE SNe light curves, computed here with the KEPLER code, are distinctively faint, red, and long-lived, making them challenging to find with transient surveys. The accompanying shock breakouts are brighter, though briefer, and potentially easier to detect. Previous analytic work provides general guidance, but numerical simulations are challenging due to the range of conditions and lack of equilibration between color and effective temperatures. We consider previous analytic work and extend discussions of color temperature and opacity to the lower energy range explored by these events. Since this is the first application of the CASTRO code to shock breakout, test simulations of normal energy shock breakout of SN1987A are carried out and compared with the literature. A set of breakout light curves and spectra are then calculated for VLE SNe with final kinetic energies in the range 10 47 − 10 50 ergs for red supergiants with main sequence masses 15 M and 25 M . The importance of uncertainties in stellar atmosphere model, opacity, and ambient medium is discussed, as are observational prospects with current and forthcoming missions.

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Castro: A New Compressible Astrophysical Solver. I. Hydrodynamics and Self-Gravity

Cited by 264 publications

References 42 publications

The Development of Explosions in Axisymmetric Ab Initio Core-Collapse Supernova Simulations of 12–25 Stars

The Development of Explosions in Axisymmetric Ab Initio Core-Collapse Supernova Simulations of 12–25 Stars

White Dwarf Mergers on Adaptive Meshes. I. Methodology and Code Verification

Very Low-energy Supernovae: Light Curves and Spectra of Shock Breakout

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