Optical EVPA rotations in blazars: testing a stochastic variability model with RoboPol data

Abstract

We identify rotations of the polarization angle in a sample of blazars observed for three seasons with the RoboPol instrument. A simplistic stochastic variability model is tested against this sample of rotation events. The model is capable of producing samples of rotations with parameters similar to the observed ones, but fails to reproduce the polarization fraction at the same time. Even though we can neither accept nor conclusively reject the model, we point out various aspects of the observations that are fully consistent with a random walk process.

17 pages, 18 figures, 4 tables. Accepted 2017 August 17 for publication in MNRAS

References in corpus (6)

• Probing the Inner Jet of the Quasar PKS 1510-089 with Multi-waveband Monitoring during Strong Gamma-ray Activity
• Results of WEBT, VLBA and RXTE monitoring of 3C 279 during 2006-2007
• RoboPol: The optical polarization of gamma-ray--loud and gamma-ray--quiet blazars
• Polarization Swings Reveal Magnetic Energy Dissipation in Blazars
• RoboPol: Do optical polarization rotations occur in all blazars?
• Polarization swings from curved trajectories of the emitting regions

Cited by in corpus (5)

• RoboPol: Connection between optical polarization plane rotations and gamma-ray flares in blazars
• A Model of Polarisation Rotations in Blazars from Kink Instabilities in Relativistic Jets
• The RoboPol Program: Optical Polarimetric Monitoring of Blazars
• The University of Michigan Centimeter-Band All Stokes Blazar Monitoring Program: Single-Dish Polarimetry as a Probe of Parsec-Scale Magnetic Fields
• Probing the unidentified Fermi blazar-like population using optical polarization and machine learning