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Title: A comparison of two- and three-dimensional neutrino-hydrodynamics simulations of core-collapse supernovae

Abstract

We present numerical results on two- (2D) and three-dimensional (3D) hydrodynamic core-collapse simulations of an 11.2 M {sub ☉} star. By changing numerical resolutions and seed perturbations systematically, we study how the postbounce dynamics are different in 2D and 3D. The calculations were performed with an energy-dependent treatment of the neutrino transport based on the isotropic diffusion source approximation scheme, which we have updated to achieve a very high computational efficiency. All of the computed models in this work, including nine 3D models and fifteen 2D models, exhibit the revival of the stalled bounce shock, leading to the possibility of explosion. All of them are driven by the neutrino-heating mechanism, which is fostered by neutrino-driven convection and the standing-accretion-shock instability. Reflecting the stochastic nature of multi-dimensional (multi-D) neutrino-driven explosions, the blast morphology changes from model to model. However, we find that the final fate of the multi-D models, whether an explosion is obtained or not, is little affected by the explosion stochasticity. In agreement with some previous studies, higher numerical resolutions lead to slower onset of the shock revival in both 2D and 3D. Based on the self-consistent supernova models leading to the possibility of explosions, our results systematically showmore » that the revived shock expands more energetically in 2D than in 3D.« less

Authors:
;  [1];  [2]
  1. Center for Computational Astrophysics, National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)
  2. Yukawa Institute for Theoretical Physics, Kyoto University, Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 (Japan)
Publication Date:
OSTI Identifier:
22356974
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 786; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; APPROXIMATIONS; COMPUTERIZED SIMULATION; DIFFUSION; DISTURBANCES; ENERGY DEPENDENCE; EXPLOSIONS; GRAVITATIONAL COLLAPSE; HYDRODYNAMIC MODEL; NEUTRINOS; PERTURBATION THEORY; RESOLUTION; STOCHASTIC PROCESSES; SUPERNOVAE; THREE-DIMENSIONAL CALCULATIONS; TWO-DIMENSIONAL CALCULATIONS

Citation Formats

Takiwaki, Tomoya, Kotake, Kei, and Suwa, Yudai. A comparison of two- and three-dimensional neutrino-hydrodynamics simulations of core-collapse supernovae. United States: N. p., 2014. Web. doi:10.1088/0004-637X/786/2/83.
Takiwaki, Tomoya, Kotake, Kei, & Suwa, Yudai. A comparison of two- and three-dimensional neutrino-hydrodynamics simulations of core-collapse supernovae. United States. doi:10.1088/0004-637X/786/2/83.
Takiwaki, Tomoya, Kotake, Kei, and Suwa, Yudai. 2014. "A comparison of two- and three-dimensional neutrino-hydrodynamics simulations of core-collapse supernovae". United States. doi:10.1088/0004-637X/786/2/83.
@article{osti_22356974,
title = {A comparison of two- and three-dimensional neutrino-hydrodynamics simulations of core-collapse supernovae},
author = {Takiwaki, Tomoya and Kotake, Kei and Suwa, Yudai},
abstractNote = {We present numerical results on two- (2D) and three-dimensional (3D) hydrodynamic core-collapse simulations of an 11.2 M {sub ☉} star. By changing numerical resolutions and seed perturbations systematically, we study how the postbounce dynamics are different in 2D and 3D. The calculations were performed with an energy-dependent treatment of the neutrino transport based on the isotropic diffusion source approximation scheme, which we have updated to achieve a very high computational efficiency. All of the computed models in this work, including nine 3D models and fifteen 2D models, exhibit the revival of the stalled bounce shock, leading to the possibility of explosion. All of them are driven by the neutrino-heating mechanism, which is fostered by neutrino-driven convection and the standing-accretion-shock instability. Reflecting the stochastic nature of multi-dimensional (multi-D) neutrino-driven explosions, the blast morphology changes from model to model. However, we find that the final fate of the multi-D models, whether an explosion is obtained or not, is little affected by the explosion stochasticity. In agreement with some previous studies, higher numerical resolutions lead to slower onset of the shock revival in both 2D and 3D. Based on the self-consistent supernova models leading to the possibility of explosions, our results systematically show that the revived shock expands more energetically in 2D than in 3D.},
doi = {10.1088/0004-637X/786/2/83},
journal = {Astrophysical Journal},
number = 2,
volume = 786,
place = {United States},
year = 2014,
month = 5
}
  • We present the first two-dimensional general relativistic (GR) simulations of stellar core collapse and explosion with the COCONUT hydrodynamics code in combination with the VERTEX solver for energy-dependent, three-flavor neutrino transport, using the extended conformal flatness condition for approximating the space-time metric and a ray-by-ray-plus ansatz to tackle the multi-dimensionality of the transport. For both of the investigated 11.2 and 15 M{sub Sun} progenitors we obtain successful, though seemingly marginal, neutrino-driven supernova explosions. This outcome and the time evolution of the models basically agree with results previously obtained with the PROMETHEUS hydro solver including an approximative treatment of relativistic effectsmore » by a modified Newtonian potential. However, GR models exhibit subtle differences in the neutrinospheric conditions compared with Newtonian and pseudo-Newtonian simulations. These differences lead to significantly higher luminosities and mean energies of the radiated electron neutrinos and antineutrinos and therefore to larger energy-deposition rates and heating efficiencies in the gain layer with favorable consequences for strong nonradial mass motions and ultimately for an explosion. Moreover, energy transfer to the stellar medium around the neutrinospheres through nucleon recoil in scattering reactions of heavy-lepton neutrinos also enhances the mentioned effects. Together with previous pseudo-Newtonian models, the presented relativistic calculations suggest that the treatment of gravity and energy-exchanging neutrino interactions can make differences of even 50%-100% in some quantities and is likely to contribute to a finally successful explosion mechanism on no minor level than hydrodynamical differences between different dimensions.« less
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  • We present a detailed theoretical analysis of the gravitational wave (GW) signal of the post-bounce evolution of core-collapse supernovae (SNe), employing for the first time relativistic, two-dimensional explosion models with multi-group, three-flavor neutrino transport based on the ray-by-ray-plus approximation. The waveforms reflect the accelerated mass motions associated with the characteristic evolutionary stages that were also identified in previous works: a quasi-periodic modulation by prompt post-shock convection is followed by a phase of relative quiescence before growing amplitudes signal violent hydrodynamical activity due to convection and the standing accretion shock instability during the accretion period of the stalled shock. Finally, amore » high-frequency, low-amplitude variation from proto-neutron star (PNS) convection below the neutrinosphere appears superimposed on the low-frequency trend associated with the aspherical expansion of the SN shock after the onset of the explosion. Relativistic effects in combination with detailed neutrino transport are shown to be essential for quantitative predictions of the GW frequency evolution and energy spectrum, because they determine the structure of the PNS surface layer and its characteristic g-mode frequency. Burst-like high-frequency activity phases, correlated with sudden luminosity increase and spectral hardening of electron (anti-)neutrino emission for some 10 ms, are discovered as new features after the onset of the explosion. They correspond to intermittent episodes of anisotropic accretion by the PNS in the case of fallback SNe. We find stronger signals for more massive progenitors with large accretion rates. The typical frequencies are higher for massive PNSs, though the time-integrated spectrum also strongly depends on the model dynamics.« less
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