Near-Infrared Polarimetric Adaptive Optics Observations of NGC 1068: A
  torus created by a hydromagnetic outflow wind
  We present J' and K' imaging linear polarimetric adaptive optics observations
of NGC 1068 using MMT-Pol on the 6.5-m MMT. These observations allow us to
study the torus from a magnetohydrodynamical (MHD) framework. In a 0.5" (30 pc)
aperture at K', we find that polarisation arising from the passage of radiation
from the inner edge of the torus through magnetically aligned dust grains in
the clumps is the dominant polarisation mechanism, with an intrinsic
polarisation of 7.0%$\pm$2.2%. This result yields a torus magnetic field
strength in the range of 4$-$82 mG through paramagnetic alignment, and
139$^{+11}_{-20}$ mG through the Chandrasekhar-Fermi method. The measured
position angle (P.A.) of polarisation at K$'$ is found to be similar to the
P.A. of the obscuring dusty component at few parsec scales using infrared
interferometric techniques. We show that the constant component of the magnetic
field is responsible for the alignment of the dust grains, and aligned with the
torus axis onto the plane of the sky. Adopting this magnetic field
configuration and the physical conditions of the clumps in the MHD outflow wind
model, we estimate a mass outflow rate $\le$0.17 M$_{\odot}$ yr$^{-1}$ at 0.4
pc from the central engine for those clumps showing near-infrared dichroism.
The models used were able to create the torus in a timescale of $\geq$10$^{5}$
yr with a rotational velocity of $\leq$1228 km s$^{-1}$ at 0.4 pc. We conclude
that the evolution, morphology and kinematics of the torus in NGC 1068 can be
explained within a MHD framework.
