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Title: THE EVOLUTION AND IMPACTS OF MAGNETOROTATIONAL INSTABILITY IN MAGNETIZED CORE-COLLAPSE SUPERNOVAE

We carried out two-dimensional axisymmetric MHD simulations of core-collapse supernovae for rapidly rotating magnetized progenitors. By changing both the strength of the magnetic field and the spatial resolution, the evolution of the magnetorotational instability (MRI) and its impacts upon the dynamics are investigated. We found that the MRI greatly amplifies the seed magnetic fields in the regime where the buoyant mode, not the Alfvén mode, plays a primary role in the exponential growth phase. The MRI indeed has a powerful impact on the supernova dynamics. It makes the shock expansion faster and the explosion more energetic, with some models being accompanied by the collimated jet formations. These effects, however, are not made by the magnetic pressure except for the collimated jet formations. The angular momentum transfer induced by the MRI causes the expansion of the heating region, by which the accreting matter gain additional time to be heated by neutrinos. The MRI also drifts low-Y{sub p} matter from deep inside of the core to the heating region, which makes the net neutrino heating rate larger by the reduction of the cooling due to the electron capture. These two effects enhance the efficiency of the neutrino heating, which is found to be the key tomore » boosting the explosion. Indeed, we found that our models explode far more weakly when the net neutrino heating is switched off. The contribution of the neutrino heating to the explosion energy could reach 60% even in the case of strongest magnetic field in the current simulations.« less
Authors:
 [1] ;  [2]
  1. Research Organization for Information Science and Technology, Kobe, Hyogo 650-0047 (Japan)
  2. Waseda University, Shinjuku, Tokyo 169-8555 (Japan)
Publication Date:
OSTI Identifier:
22521616
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 817; 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; ANGULAR MOMENTUM TRANSFER; AXIAL SYMMETRY; COMPUTERIZED SIMULATION; ELECTRON CAPTURE; HEATING RATE; INSTABILITY; JETS; MAGNETIC FIELDS; MAGNETOHYDRODYNAMICS; NEUTRON STARS; SPATIAL RESOLUTION; SUPERNOVAE; TWO-DIMENSIONAL SYSTEMS