Magnetically Arrested Disks and Origin of Poynting Jets: Numerical Study

Understand

The dynamics and structure of accretion disks, which accumulate the vertical magnetic field in the centers, are investigated using two- and three-dimensional MHD simulations.

• The central field can be built up to the equipartition level and disrupts a nearly axisymmetric outer accretion disk inside a magnetospheric radius, forming a magnetically arrested disk (MAD).
• In the MAD, the mass accretes in a form of irregular dense spiral streams and the vertical field, split into separate bundles, penetrates through the disk plane in low-density magnetic islands.
• The accreting mass, when spiraling inward, drags the field and twists it around the axis of rotation, resulting in collimated Poynting jets in the polar directions.