The structure and evolution of protoplanetary disks (PPDs) are largely governed by disk angular momentum transport, mediated by magnetic fields. In the most observable outer disk, ambipolar diffusion is the primary non-ideal magnetohydrodynamic(MHD) effect. In this work, we study the gas dynamics in outer PPDs by conducting a series of global 3D non-ideal MHD simulations with ambipolar diffusion and net poloidal magnetic flux, using the Athena++ MHD code, with resolution comparable to local simulations. Our simulations demonstrate the co-existence of magnetized disk winds and turbulence driven by the magneto-rotational instability (MRI). While MHD winds dominate disk angular momentum transport, the MRI turbulence also contributes significantly. We observe that magnetic flux spontaneously concentrate into axisymmetric flux sheets, leading to radial variations in turbulence levels, stresses, and accretion rates. Annular substructures arise as a natural consequence of magnetic flux concentration. The flux concentration phenomena show diverse properties with different levels of disk magnetization and ambipolar diffusion. The disk generally loses magnetic flux over time, though flux sheets could prevent the leak of magnetic flux in some cases. Our results demonstrate the ubiquity of disk annular substructures in weakly MRI turbulent outer PPDs, and imply a stochastic nature of disk evolution.

The mechanisms of angular momentum transport and the level of turbulence in protoplanetary disks (PPDs) are crucial for understanding many aspects of planet formation. In recent years, it has been realized that the magneto-rotational instability (MRI) tends to be suppressed in PPDs due to non-ideal magnetohydrodynamic (MHD) effects, and the disk is primarily laminar with accretion driven by magnetized disk winds. In parallel, several hydrodynamic mechanisms have been identified that likely also generate vigorous turbulence and drive disk accretion. In this work, we study the interplay between MHD winds in PPDs with the vertical shear instability (VSI), one of the most promising hydrodynamic mechanisms, through 2D global non-ideal MHD simulations with ambipolar diffusion and Ohmic resistivity. For typical disk parameters, MHD winds can coexist with the VSI with accretion primarily wind-driven accompanied by vigorous VSI turbulence. The properties of the VSI remain similar to the unmagnetized case. The wind and overall field configuration are not strongly affected by the VSI turbulence showing modest level of variability and corrugation of midplane current sheet. Weak ambipolar diffusion strength or the enhanced coupling between gas and magnetic fields weakens the VSI. The VSI is also weakened with increasing magnetization, and characteristic VSI corrugation modes transition to low-amplitude breathing mode oscillations with strong magnetic fields.

From a Chandra sample of active galactic nuclei (AGNs) in nearby galaxies, we find that for lowluminosity AGNs (LLAGNs), either the intrinsic absorption column density, or the fraction of absorbed AGNs, positively scales with the Eddington ratio for L bol /L Edd 10 −2 . Such a behavior, along with the softness of the X-ray spectrum at low luminosities, is in good agreement with the picture that they are powered by hot accretion flows surrounding supermassive black holes. Numerical simulations find that outflows are inevitable with hot accretion flows, and the outflow rate is correlated with the innermost accretion rate in the low-luminosity regime. This agrees well with our results, suggesting that the X-ray absorption originates from or is associated with the outflow material. Gas and dust on larger scales may also produce the observed correlation. Future correlation analysis may help differentiate the two scenarios.

The great difference in dynamical range between small-scale accretion disk simulations and largescale or cosmological simulations places difficulties in tracking disk wind kinematics. In the first paper of this series, we have studied dynamics of hydrodynamic winds from the outer edge of the accretion disk towards galactic scales. In this paper, we further incorporate magnetic fields by employing one-dimensional magnetohydrodynamic (MHD) model, with fiducial boundary conditions set for hot accretion flows. The wind solution is achieved through requesting gas to pass through the slow, Alfvén and fast magneto-sonic points smoothly. Beyond the fast magneto-sonic point, physical quantities are found to show power-law dependences with cylindrical radiusThe 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 about 0.016c. The dependance of wind physical quantities on temperature, field line angular velocity, and adiabatic index is also discussed.