Tilted Disks Around Black Holes: Elucidating the Alignment Mechanism
This project will use Blue Waters to significantly extend the investigators' ongoing study of astrophysical accretion onto a spinning black hole when there is a misalignment between the orbital axis of the incoming gas and the black hole's rotation axis. Such a misalignment induces a relativistic torque on the accretion disk. Astrophysicists have long expected that an initially misaligned orbiting accretion disk would align with the black hole's spin axis at some location near the hole. A detailed understanding of this alignment process has, however, been limited due to the assumption of a phenomenological viscosity to describe the internal dissipation. Instead of phenomenological viscosity, the planned simulation will use only the known internal stress due to magnetohydrodynamic. The investigation will probe the mechanisms by which a time-steady transition might be achieved between an inner disk region aligned with the equatorial plane of the central mass's spin and an outer region orbiting in a different plane.