Optical polarization in the relativistic jets

Ryosuke Itoh

Relativistic jets are extremely powerful and fast outflow of plasma and emerges from the vicinity of the massive black hole. Polarized radiation from relativistic jet is one key piece of evidence for synchrotron radiation in the optical band and it also varies drastically.
The polarization of jet is of interest for understanding the origin, confinement, and propagation of jets. However, even though numerous measurements have been performed,
the mechanisms behind jet variability, creation, and composition are still debated.

The polarization variability in relativistic jet is generally observed to be erratic.
But several unique event (e.g., rotation of polarization angle) during outburst were reported, which might be related with the structure of magnetic field in the relativistic jets.
Recently, systematic studies of these phenomena are also performed. I review recent progress in the polarimetric observation of relativistic jets and show our observation results of relativistic jet.