Behind the scenes of protostellar disks: formation and fragmentation
Research report (imported) 2017 - Max Planck Institute for extraterrestrial Physics
For a long time the formation of protostellar disks – a prerequisite to the formation of planetary system around stars – was considered to be difficult. The magnetic field threading the dense rotating molecular cloud is dragged to the center by the gravitational collapse, resulting in a braking effect that carries away angular momentum from the central region. Hardly any rotationally supported disk can form this way, unless the tiny grains are removed from the cloud and the separation between the magnetic field and the collapsing flow is enhanced.