A new multi-energy neutrino radiation-hydrodynamics code in full general relativity and its application to the gravitational collapse of massive stars

Journal Article · Mon Feb 01 04:00:00 EST 2016 · Astrophysical Journal, Supplement Series

DOI:https://doi.org/10.3847/0067-0049/222/2/20· OSTI ID:22872391

Kuroda, Takami ^[1]; Takiwaki, Tomoya ^[2]; Kotake, Kei ^[3]

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1. Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel (Switzerland)
2. Astrophysical Big Bang Laboratory, RIKEN, Saitama, 351-0198 (Japan)
3. Department of Applied Physics, Fukuoka University, 8-19-1, Jonan, Nanakuma, Fukuoka, 814-0180 (Japan)

We present a new multi-dimensional radiation-hydrodynamics code for massive stellar core-collapse in full general relativity (GR). Employing an M1 analytical closure scheme, we solve spectral neutrino transport of the radiation energy and momentum based on a truncated moment formalism. Regarding neutrino opacities, we take into account a baseline set in state-of-the-art simulations, in which inelastic neutrino–electron scattering, thermal neutrino production via pair annihilation, and nucleon–nucleon bremsstrahlung are included. While the Einstein field equations and the spatial advection terms in the radiation-hydrodynamics equations are evolved explicitly, the source terms due to neutrino–matter interactions and energy shift in the radiation moment equations are integrated implicitly by an iteration method. To verify our code, we first perform a series of standard radiation tests with analytical solutions that include the check of gravitational redshift and Doppler shift. A good agreement in these tests supports the reliability of the GR multi-energy neutrino transport scheme. We then conduct several test simulations of core-collapse, bounce, and shock stall of a 15M{sub ⊙} star in the Cartesian coordinates and make a detailed comparison with published results. Our code performs quite well to reproduce the results of full Boltzmann neutrino transport especially before bounce. In the postbounce phase, our code basically performs well, however, there are several differences that are most likely to come from the insufficient spatial resolution in our current 3D-GR models. For clarifying the resolution dependence and extending the code comparison in the late postbounce phase, we discuss that next-generation Exaflops class supercomputers are needed at least.

• OSTI ID: 22872391
• Journal Information: Astrophysical Journal, Supplement Series, Journal Name: Astrophysical Journal, Supplement Series Journal Issue: 2 Vol. 222; ISSN 0067-0049; ISSN APJSA2
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ANALYTICAL SOLUTION
ANNIHILATION
BOLTZMANN EQUATION
BREMSSTRAHLUNG
CARTESIAN COORDINATES
DOPPLER EFFECT
EINSTEIN FIELD EQUATIONS
GRAVITATIONAL COLLAPSE
HYDRODYNAMICS
NEUTRINO-ELECTRON INTERACTIONS
NUCLEON-NUCLEON INTERACTIONS
RED SHIFT
SPATIAL RESOLUTION
SUPERCOMPUTERS