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We investigate the effects of rotation on the evolution of core-collapse supernova explosion using a 15 solar mass progenitor model with a variety of neutrino luminosity and rotational velocity. Stars should have some amount of angular momentum, which would affect stellar evolution and its final explosion. In this paper we focus on the effect of rotation on gravitational collapse of a core, on a core bounce of accreting matter, and on subsequent generation and evolution of a shock wave. We find that the rotation plays a positive role for supernova explosions. More rapidly rotating models present more rapid expansion of the shock front and more energetic explosions. When the rotational speed is moderate, the shock once stalls at about 200 km away from the center similarly to a non-rotating model. Then the rotating progenitor experiences effective neutrino heating especially around an equatorial plane and explodes even with somewhat low neutrino luminosity for which the non-rotating model cannot overcome accreting matter and finally collapses. When the rotational speed is fast, the shock expands to about 300 km immediately after the core bounce and then evolves to move outward without shock stalling. We conclude that this positive effect of rotation to explosions is dominant against some possible negative aspects, for example, lower neutrino luminosity caused by less contraction of the rotating core.

We calculate the neutrino production cross-section in the proto-neutron-star matter under a strong magnetic field in the relativistic mean-field approach. We introduce a new parameter-set which can reproduce the 1.96 solar mass neutron star. We find that the production process increases emitted neutrinos along the direction parallel to the magnetic field and decrease those along its opposite direction. It means that resultant asymmetry due to the neutrino absorption and scattering process in the magnetic field becomes larger by the addition of the neutrino production process.

Core‐collapse supernovae (CCSNe) are the final fate of the massive stars, but their explosion mechanisms are still uncertain. One of the clues to the solution of the explosion mechanism is to examine the asymmetric effects. This is because most of observed CCSNe are asymmetric explosions. One of the factors to the asymmetric explosions are the magnetorotational effects. The magnetic fields are amplified intensively along the rotational axsis during the collapse, and it leads to the bipolar outflows which may eject outer mantle. To understand the role of magnetorotational effects during CCSNe, we have developed a new multidimensional magnetohydrodynamic(MHD) code and calculate collapse of a 25 M⊙ star with various magnetic field and rotational velocity.