Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published December 2017 | Submitted + Published
Journal Article Open

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


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.

Additional Information

© 2017 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. Accepted 2017 August 17. Received 2017 August 16; in original form 2017 June 8. Published: 23 August 2017. The RoboPol project is a collaboration between the University of Crete/FORTH in Greece, Caltech in the USA, MPIfR in Germany, IUCAA in India and Toruń Centre for Astronomy in Poland. This research was supported in part by NASA grants NNX11A043G and NNX16AR41G and NSF grant AST-1109911. SK is supported through NASA grant NNX13AQ89G. This research was partly funded by the Academy of Finland project 284495. SK particularly thanks T. Savolainen for comments on this manuscript and for the support of this research. The authors furthermore thank E. Angelakis, T. Hovatta, V. Pavlidou and K. Tassis from the RoboPol collaboration for comments and intense discussions during the collaboration meetings. This research was done with PYTHON packages NUMPY 1.11.3—, SCIPY 0.18.1—, STATSMODELS 0.6.1—, PYTABLES 3.3.0— and MATPLOTLIB 2.0.0—.

Attached Files

Published - stx2167.pdf

Submitted - 1708.06777.pdf


Files (10.9 MB)
Name Size Download all
7.3 MB Preview Download
3.6 MB Preview Download

Additional details

August 19, 2023
October 17, 2023