| Propeller-driven outflows have recently been found and studied in our axisymmetric magnetohydrodynamic simulations of disk accretion to rapidly rotating magnetized stars. Matter outflows in a wide cone and is centrifugally ejected from the inner regions of the disk. Closer to the axis there is a strong, collimated, magnetically-dominated or Poynting flux jet of energy and angular momentum carried mainly by the open magnetic field from the star. The ``efficiency'' of the propeller may be very high in the respect that most of the incoming disk matter is expelled from the system in winds. The star spins-down rapidly due to the magnetic interaction with the disk through closed field lines and with corona through open field lines. Diffusive and viscous interaction between magnetosphere and the disk are important: no outflows were observed for very small values of the diffusivity and viscosity. The simulation results are applicable to the early stages of evolution of classical T Tauri stars and to different stages of evolution of cataclysmic variables and neutron stars in binary systems. |
Tuesday, April 11th
Seminar is to be held at 4:00 PM in the conference room
on the second floor of Dearborn Observatory
Refreshments will be served at 3:30
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