JVLA Wideband Polarimetry Observations on a Sample of High Rotation
  Measure Sources
  We present preliminary results of JVLA wideband full polarization
observations of a sample of Active Galactic Nuclei (AGN) with very high
Rotation Measure (RM) values, a sign of extreme environment. Polarization
properties show a complex behaviour such that the polarization angle (PA) and
fractional polarization (fp) change dramatically within the wide band. The
measured RM is not constant within the wide band. Its complex behaviour
reflects the complexity of the medium with the presence of several Faraday
components. The depolarization has been studied by modelling the variations of
the Stokes parameters Q and U together with the polarization parameters (PA and
fp) with wavelength using combinations of the simplest existing depolarization
models. With this JVLA study we could spectrally resolve multiple polarized
components of unresolved AGN. These preliminary results reveal the complexity
of these objects, but improvements to the depolarization modelling are needed
to better understand the polarization structure of these sources.
