Estimations of the magnetic field strength in the torus of AGN using
  near-infrared polarimetry
  An optically and geometrically thick torus obscures the central engine of
Active Galactic Nuclei (AGN) from some lines of sight. From a
magnetohydrodynamical framework, the torus can be considered to be a particular
region of clouds surrounding the central engine where the clouds are dusty and
optically thick. In this framework, the magnetic field plays an important role
in the creation, morphology and evolution of the torus. If the dust grains
within the clouds are assumed to be aligned by paramagnetic alignment, then the
ratio of the intrinsic polarisation and visual extinction, P(%)/Av, is a
function of the magnetic field strength.
  To estimate the visual extinction through the torus and constrain the
polarisation mechanisms in the nucleus of AGN, we developed a polarisation
model to fit both the total and polarised flux in a 1.2" (~263pc) aperture of
the type 2 AGN, IC5063. The polarisation model is consistent with the nuclear
polarisation observed at K being produced by dichroic absorption from aligned
dust grains with a visual extinction through the torus of 48$\pm$2 mag. We
estimated the intrinsic polarisation arising from dichroic absorption to be
P$_{K}^{dic}$=12.5$\pm$2.7%.
  We consider the physical conditions and environment of the gas and dust for
the torus of IC5063. Then, through paramagnetic alignment, we estimate a
magnetic field strength in the range of 12-128mG in the NIR emitting regions of
the torus of IC5063. Alternatively, we estimate the magnetic field strength in
the plane of the sky using the Chandrasekhar-Fermi method. The minimum magnetic
field strength in the plane of the sky is estimated to be 13 and 41 mG
depending of the conditions within the torus of IC5063. These techniques afford
the chance to make a survey of AGN, to investigate the effects of magnetic
field strength on the torus, accretion, and interaction to the host galaxy.
