|MHD Simulations of Non-rotating Stellar Core Collapse
|459, 6th International Conference of Numerical Modeling of Space Plasma Flows (ASTRONUM 2011)
|Obergaulinger, M.; Janka, T.
|Using a new code for the solution of the coupled equations of
magnetohydrodynamics (MHD) and neutrino transport, we simulate the
collapse and post-bounce evolution of the core of a non-rotating
massive star endowed with a poloidal magnetic field. Our code
solves the hyperbolic system of the two-moment equations for the
transport of electron neutrinos and antineutrinos and the MHD
equations in a finite-volume discretisation using high-resolution
shock capturing methods. The coupling between the neutrinos and the
gas is accounted for by the most important weak interactions.
Although the absence of rotation restricts the possible mechanisms
for the amplification of the magnetic field, we find a strong growth
of the initial field by flux-freezing compression during collapse
and by hydrodynamic instabilities afterwards. From an initial field
comparable to the results of current stellar-evolution calculations,
the core reaches a field strength in the range observed typically at
the surface of pulsars, while a much stronger initial field gives
rise to magnetar-like final fields.