RoboPol: connection between optical polarization plane rotations and gamma-ray flares in blazars
: D. Blinov, V. Pavlidou, I. Papadakis, S. Kiehlmann, I. Liodakis, G. V. Panopoulou, E. Angelakis, M. Balokovi´c, T. Hovatta, O. G. King, A. Kus, N. Kylafis, A. Mahabal, S. Maharana, I. Myserlis, E. Paleologou, I. Papamastorakis, E. Pazderski, T. J. Pearson, A. Ramaprakash, A. C. S. Readhead, P. Reig, K. Tassis, J. A. Zensus
Publisher: OXFORD UNIV PRESS
: 2018
: Monthly Notices of the Royal Astronomical Society
: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
: MON NOT R ASTRON SOC
: 474
: 1
: 1296
: 1306
: 11
: 0035-8711
DOI: https://doi.org/10.1093/mnras/stx2786
: https://research.utu.fi/converis/portal/detail/Publication/30133792
We use results of our 3 yr polarimetric monitoring programme to investigate the previously suggested connection between rotations of the polarization plane in the optical emission of blazars and their gamma-ray flares in the GeV band. The homogeneous set of 40 rotation events in 24 sources detected by RoboPol is analysed together with the gamma-ray data provided by Fermi-LAT. We confirm that polarization plane rotations are indeed related to the closest gamma-ray flares in blazars and the time lags between these events are consistent with zero. Amplitudes of the rotations are anticorrelated with amplitudes of the gamma-ray flares. This is presumably caused by higher relativistic boosting (higher Doppler factors) in blazars that exhibit smaller amplitude polarization plane rotations. Moreover, the time-scales of rotations and flares are marginally correlated.