Discs, outflows, and feedback in collapsing magnetized cores

TL;DR

This paper uses 3D simulations to study how magnetic fields influence early protostellar disc formation, revealing that magnetic braking and outflows can suppress disc formation and carry away mass and angular momentum.

Contribution

It demonstrates that strong magnetic torques in magnetized cores produce transient discs and large outflows, highlighting magnetic effects on early star formation.

Findings

Transient 1000 AU discs form in simulations

Large outflows carry away mass and angular momentum

Magnetic braking suppresses rotationally supported discs

Abstract

The pre-stellar cores in which low mass stars form are generally well magnetized. Our simulations show that early protostellar discs are massive and experience strong magnetic torques in the form of magnetic braking and protostellar outflows. Simulations of protostellar disk formation suggest that these torques are strong enough to suppress a rotationally supported structure from forming for near critical values of mass-to-flux. We demonstrate through the use of a 3D adaptive mesh refinement code -- including cooling, sink particles and magnetic fields -- that one produces transient 1000 AU discs while simultaneously generating large outflows which leave the core region, carrying away mass and angular momentum. Early inflow/outflow rates suggest that only a small fraction of the mass is lost in the initial magnetic tower/jet event.