Outflows and Jets from Collapsing Magnetized Cloud Cores

Star formation is usually accompanied by outflow phenomena. There is strong evidence that these outflows and jets are launched from protostellar disks by magnetorotational processes. Here we report on our three-dimensional, adaptive mesh, magnetohydrodynamic simulations of collapsing, rotating, magnetized Bonnor-Ebert spheres, whose properties are taken directly from observations. In contrast to the pure hydro case, in which no outflows are seen, our present simulations show an outflow from the protodisk surface at ~130 AU and a jet at ~0.07 AU after a strong toroidal magnetic field buildup. The large-scale outflow, which extends up to ~600 AU at the end of our simulation, is driven by toroidal magnetic pressure (spring), whereas the jet is powered by magnetocentrifugal force (fling). At the final stage of our simulation these winds are still confined within two respective shock fronts. Furthermore, we find that the jet-wind and the disk-anchored magnetic field extract a considerable amount of angular momentum from the protostellar disk. The initial spin of our cloud core was chosen high enough to produce a binary system. We indeed find a close binary system (separation ~3 R☉), which results from the fragmentation of an earlier formed ring structure. The magnetic field strength in these protostars reaches ~3 kG and becomes about 3 G at 1 AU from the center, in agreement with recent observational results.