Three‐dimensional Simulations of Disk Accretion to an Inclined Dipole. I. Magnetospheric Flows at Different Θ

We present results of fully three-dimensional MHD simulations of diskaccretion to a rotating magnetized star with its dipole moment inclined at anangle Theta to the rotation axis of the disk. We observed that matter accretesfrom the disk to a star in two or several streams depending on Theta. Streamsmay precess around the star at small Theta. The inner regions of the disk arewarped. The warping is due to the tendency of matter to co-rotate with inclinedmagnetosphere. The accreting matter brings positive angular momentum to the(slowly rotating) star tending to spin it up. The corresponding torque N_zdepends only weakly on Theta. The angular momentum flux to the star istransported predominantly by the magnetic field; the matter componentcontributes < 1 % of the total flux. Results of simulations are important forunderstanding the nature of classical T Tauri stars, cataclysmic variables, andX-ray pulsars.