Polarization angle swings in blazars: The case of 3C 279
Abstract
Over the past few years, several occasions of large, continuous rotations of the electric vector position angle (EVPA) of linearly polarized optical emission from blazars have been reported. These events are often coincident with high energy gamma-ray flares and they have attracted considerable attention, as they could allow one to probe the magnetic field structure in the gamma-ray emitting region of the jet. The flat-spectrum radio quasar 3C279 is one of the most prominent examples showing this behaviour. Our goal is to study the observed EVPA rotations and to distinguish between a stochastic and a deterministic origin of the polarization variability. We have combined multiple data sets of R-band photometry and optical polarimetry measurements of 3C279, yielding exceptionally well-sampled flux density and polarization curves that cover a period of 2008-2012. Several large EVPA rotations are identified in the data. We introduce a quantitative measure for the EVPA curve smoothness, which is then used to test a set of simple random walk polarization variability models against the data. 3C279 shows different polarization variation characteristics during an optical low-flux state and a flaring state. The polarization variation during the flaring state, especially the smooth approx. 360 degrees rotation of the EVPA in mid-2011, is not consistent with the tested stochastic processes. We conclude that during the two different optical flux states, two different processes govern the polarization variation, possibly a stochastic process during the low-brightness state and a deterministic process during the flaring activity.
Keywords
Cite
@article{arxiv.1603.00249,
title = {Polarization angle swings in blazars: The case of 3C 279},
author = {S. Kiehlmann and T. Savolainen and S. G. Jorstad and K. V. Sokolovsky and F. K. Schinzel and A. P. Marscher and V. M. Larionov and I. Agudo and H. Akitaya and E. Benítez and A. Berdyugin and D. A. Blinov and N. G. Bochkarev and G. A. Borman and A. N. Burenkov and C. Casadio and V. T. Doroshenko and N. V. Efimova and Y. Fukazawa and J. L. Gómez and T. S. Grishina and V. A. Hagen-Thorn and J. Heidt and D. Hiriart and R. Itoh and M. Joshi and K. S. Kawabata and G. N. Kimeridze and E. N. Kopatskaya and I. V. Korobtsev and T. Krajci and O. M. Kurtanidze and S. O. Kurtanidze and E. G. Larionova and L. V. Larionova and E. Lindfors and J. M. López and I. M. McHardy and S. N. Molina and Y. Moritani and D. A. Morozova and S. V. Nazarov and M. G. Nikolashvili and K. Nilsson and N. G. Pulatova and R. Reinthal and A. Sadun and M. Sasada and S. S. Savchenko and S. G. Sergeev and L. A. Sigua and P. S. Smith and M. Sorcia and O. I. Spiridonova and K. Takaki and L. O. Takalo and B. Taylor and I. S. Troitsky and M. Uemura and L. S. Ugolkova and T. Ui and M. Yoshida and J. A. Zensus and V. E. Zhdanova},
journal= {arXiv preprint arXiv:1603.00249},
year = {2016}
}
Comments
19 pages, 15 figures, 6 tables