Polarization Features of AGN Dusty Plasmas

Faraday rotation provides a direct diagnostic for the presence of magnetized material through observations of the change in the state of polarization with the frequency, as the radiation passes through the magneto-ionic media along the line of sight. The normal rotation of the plane of polarization as it propagates through a region with a magnetic field, should also be affected by the ions and dust in the plasma. In many situations electrons are the dominant factor affecting polarization. Here, we discuss astrophysical conditions where the contribution of dust and ions are significant, comparable to that of electrons.