AGN Jets and Winds in Polarised Light: The Case of Mrk 231
  We present the results of a multi-frequency, multi-scale radio polarimetric
study with the Very Large Array (VLA) of the Seyfert 1 galaxy and BALQSO, Mrk
231. We detect complex total and polarized intensity features in the source.
Overall, the images indicate the presence of a broad, one-sided, curved outflow
towards the south which consists of a weakly collimated jet with poloidal
inferred magnetic fields, inside a broader magnetized ``wind'' or ``sheath''
component with toroidal inferred magnetic fields. The model of a kpc-scale
weakly collimated jet/lobe in Mrk 231 is strengthened by its C-shaped
morphology, steep spectral index throughout, complexities in the magnetic field
structures, and the presence of self-similar structures observed on the
10-parsec-scale in the literature. The ``wind'' may comprise both nuclear
starburst (close to the core) and AGN winds, where the latter maybe the primary
contributor. Moving away from the core, the ``wind'' component may also
comprise the outer layers (or ``sheath'') of a broadened jet. The inferred
value of the (weakly collimated) jet production efficiency,
$\eta_\mathrm{jet}\sim$0.01 is consistent with the estimates in the literature.
The composite jet and wind outflow in Mrk 231 appears to be low-power and
matter-dominated, and oriented at a small angle to our line of sight.
