Magnetorotational core collapse of possible GRB progenitors. III. Three-dimensional models

Understand

We explore the influence of non-axisymmetric modes on the dynamics of the collapsed core of rotating, magnetized high-mass stars in three-dimensional simulations of a rapidly rotating star with an initial mass of $M_{ZAMS}$ = 35 solar masses endowed with four different pre-collapse configurations of the magnetic field, ranging from moderate to very strong field strength and including the field predicted by the stellar evolution model.

• The model with the weakest magnetic field achieves shock revival due to neutrino heating in a gain layer characterized by a large-scale, hydrodynamic m = 1 spiral mode.
• Later on, the growing magnetic field of the proto-neutron star launches weak outflows into the early ejecta.
• Their orientation follows the evolution of the rotational axis of the proto-neutron star, which starts to tilt from the original orientation due to the asymmetric accretion flows impinging on its surface.