Structures of magnetized thin accretion disks

We investigate the magnetohydrodynamic (MHD) process in thin accretion disks. The relevant momentum as well as magnetic reduction equations in the thin disk approximation are included. On the basis of these equations, we examine numerically the stationary structures, including distributions of the surface mass density, temperature and flow velocities of a disk around a young stellar object (YSO). The numerical results are as follows: (i) There should be an upper limit to the magnitude of magnetic field, such an upper limit corresponds to the equipartition field. For relevant magnitude of magnetic field of the disk’s interior the disk remains approximately Keplerian. (ii) The distribution of effective temperature T(r) is a smoothly decreasing function of radius with power index γ -1/2, corresponding to the observed radiation flux density, provided that the magnetic field is suitably chosen.