Long-term evolution of a merger-remnant neutron star in general relativistic magnetohydrodynamics I: Effect of magnetic winding

Understand

Long-term ideal and resistive magnetohydrodynamics (MHD) simulations in full general relativity are performed for a massive neutron star formed as a remnant of binary neutron star mergers.

• Neutrino radiation transport effects are taken into account as in our previous papers.
• The simulation is performed in axial symmetry and without considering dynamo effects as a first step.
• In the ideal MHD, the differential rotation of the remnant neutron star amplifies the magnetic-field strength by the winding in the presence of a seed poloidal field until the electromagnetic energy reaches $\sim 10\%$ of the rotational kinetic energy, $E_{\rm kin}$, of the neutron star.