INTERPLAY OF NEUTRINO OPACITIES IN CORE-COLLAPSE SUPERNOVA SIMULATIONS

Journal Article · Tue Nov 20 04:00:00 EST 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/760/1/94· OSTI ID:22086292

Lentz, Eric J ^[1]; Mezzacappa, Anthony; Hix, W Raphael ^[2]; Messer, O E. Bronson ^[3]

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1. Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996-1200 (United States)
2. Physics Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6354 (United States)
3. National Center for Computational Sciences, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6164 (United States)

We have conducted a series of numerical experiments using spherically symmetric, general relativistic, neutrino radiation hydrodynamics with the code Agile-BOLTZTRAN to examine the effects of modern neutrino opacities on the development of supernova simulations. We test the effects of opacities by removing opacities or by undoing opacity improvements for individual opacities and groups of opacities. We find that improvements to electron capture (EC) on nuclei, namely EC on an ensemble of nuclei using modern nuclear structure models rather than the simpler independent-particle approximation (IPA) for EC on a mean nucleus, plays the most important role during core collapse of all tested neutrino opacities. Low-energy neutrinos emitted by modern nuclear EC preferentially escape during collapse without the energy downscattering on electrons required to enhance neutrino escape and deleptonization for the models with IPA nuclear EC. During shock breakout the primary influence on the emergent neutrinos arises from non-isoenergetic scattering (NIS) on electrons. For the accretion phase, NIS on free nucleons and pair emission by e {sup +} e {sup -} annihilation have the largest impact on the neutrino emission and shock evolution. Other opacities evaluated, including nucleon-nucleon bremsstrahlung and especially neutrino-positron scattering, have little measurable impact on neutrino emission or shock dynamics. Modern treatments of nuclear EC, e {sup +} e {sup -}-annihilation pair emission, and NIS on electrons and free nucleons are critical elements of core-collapse simulations of all dimensionality.

• OSTI ID: 22086292
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 760; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ANNIHILATION
APPROXIMATIONS
ASTRONOMY
ASTROPHYSICS
BREMSSTRAHLUNG
COMPUTERIZED SIMULATION
COSMIC ELECTRONS
COSMIC NEUTRINOS
COSMIC POSITRONS
ELECTRON CAPTURE
GRAVITATIONAL COLLAPSE
HYDRODYNAMICS
NUCLEAR STRUCTURE
NUCLEONS
OPACITY
PHOTON EMISSION
RADIANT HEAT TRANSFER
RELATIVISTIC RANGE
SUPERNOVAE