Magnetohydrodynamic Turbulence Powered by Magnetorotational Instability in Nascent Proto-Neutron Stars

Understand

Magnetorotational instability (MRI) in a convectively-stable layer around the neutrinosphere is simulated by a three-dimensional model of supernova core.

• To resolve MRI-unstable modes, a thin layer approximation considering only the radial global stratification is adopted.
• Our intriguing finding is that the convectively-stable layer around the neutrinosphere becomes fully-turbulent due to the MRI and its nonlinear penetration into the strongly-stratified MRI-stable region.
• The intensity of the MRI-driven turbulence increases with magnetic flux threading the core, but is limited by a free energy stored in the differential rotation.