Large-scale Dynamics of Winds Originating from Black Hole Accretion Flows. II. Magnetohydrodynamics

Abstract

Abstract The great difference in dynamical range between small-scale accretion disk simulations and large-scale or cosmological simulations creates difficulties in tracking the disk wind kinematics. In the first paper of this series, we studied the dynamics of hydrodynamic winds from the outer edge of the accretion disk toward galactic scales. In this paper, we further incorporate magnetic fields by employing a one-dimensional magnetohydrodynamic model, with fiducial boundary conditions set for hot accretion flows. The wind solution is achieved through requiring gas to pass smoothly through the slow, Alfvén, and fast magnetosonic points. Beyond the fast magnetosonic point, physical quantities are found to show power-law dependences with cylindrical radius R, i.e., and . The magnetization of wind is dominant in determining the wind properties. The wind is accelerated to greater terminal velocities with stronger magnetizations. The fiducial parameters result in a terminal velocity of about 0.016c. The dependence of the wind physical quantities on temperature, field line angular velocity, and adiabatic index is also discussed.