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Related papers: RoboPol: Do optical polarization rotations occur i…

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We present measurements of rotations of the optical polarization of blazars during the second year of operation of RoboPol, a monitoring programme of an unbiased sample of gamma-ray bright blazars specially designed for effective detection…

The RoboPol instrument and the relevant program was developed in order to conduct a systematic study of the optical polarisation variability of blazars. Driven by the discovery that long smooth rotations of the optical polarisation plane…

We present first results on polarization swings in optical emission of blazars obtained by RoboPol, a monitoring program of an unbiased sample of gamma-ray bright blazars specially designed for effective detection of such events. A possible…

After three years of polarimetric monitoring of blazars, the RoboPol project has uncovered several key characteristics of polarimetric rotations in the optical for these most variable sources. The most important of these is that…

High Energy Astrophysical Phenomena · Physics 2019-04-11 Dmitry Blinov , Vasiliki Pavlidou

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…

High Energy Astrophysical Phenomena · Physics 2017-09-12 S. Kiehlmann , D. Blinov , T. J. Pearson , I. Liodakis

We use results of our 3 year polarimetric monitoring program 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…

The RoboPol program has been monitoring the $R$-band linear polarisation parameters of an unbiased sample of 60 gamma-ray-loud blazars and a "control" sample of 15 gamma-ray-quite ones. The prime drive for the program has been the…

Blazars are known for their extreme variability across the electromagnetic spectrum. Variability at very short timescales can push the boundaries between competing models offering us much needed discriminating power. This is particularly…

At optical wavelengths, blazar Electric Vector Position Angle (EVPA) rotations linked with gamma-ray activity have been the subject of intense interest and systematic investigation for over a decade. One difficulty in the interpretation of…

We present an automated pipeline for the detection of EVPA rotations in blazars, integrating correction of the 180$^\circ$ ambiguity, Bayesian Blocks segmentation, and statistical validation. Applied to RoboPol monitoring data, the method…

High Energy Astrophysical Phenomena · Physics 2026-05-20 Anastasia Glykopoulou , Ioannis Liodakis , Dmitry Blinov

Blazars are highly variable active galactic nuclei which emit radiation at all wavelengths from radio to gamma-rays. Polarized radiation from blazars is one key piece of evidence for synchrotron radiation at low energies and it also varies…

The optical polarization plane of some blazars occasionally exhibits smooth hundred degree long rotations. Multiple theoretical models have been proposed to explain the nature of such events. A deterministic origin of these rotations,…

We investigate the temporal variability of polarization of synchrotron radiation from blazar jets. Multiwavelength observations revealed high-amplitude rotations of the electric vector position angle (EVPA), both in the optical and in the…

High Energy Astrophysical Phenomena · Physics 2026-01-13 Filippo Bolis , Emanuele Sobacchi , Fabrizio Tavecchio

We describe a geometric model for synchrotron radiation from blazar jets, involving multiple emission zones with turbulent magnetic fields and a transient core with a helical B field. Including the effects of jet divergence, particle…

High Energy Astrophysical Phenomena · Physics 2018-09-19 A. L. Peirson , Roger W. Romani

Rotations of the electric vector position angle (EVPA) in blazars are often close to an integral multiple of 180$^\circ$. There are multiple examples of this in the literature, and our analysis here, of the optical polarization data from…

High Energy Astrophysical Phenomena · Physics 2020-04-22 Marshall H. Cohen , Tuomas Savolainen

Observations of quasars show that the polarization position angle of the emission coming from them varies greatly over time, including periods called rotations during which the angle changes in an orderly manner. The study proposes a method…

Blazars are thought to possess a relativistic jet that is pointing toward the direction of the Earth and the elect of relativistic beaming enhances its apparent brightness. They radiate in all wavebands from the radio to the gamma-ray bands…

High Energy Astrophysical Phenomena · Physics 2015-02-11 Ryosuke Itoh , Yasushi FUkazawa , Yasuyuki T. Tanaka , Makoto Uemura , Koji S. Kawabata , Hiroshi Akitaya , Kenji Kawaguchi , Yuka Kanda

The polarization signatures of the blazar emissions are known to be highly variable. In addition to small fluctuations of the polarization angle around a mean value, sometimes large (> 180^o) polarization angle swings are observed. We…

High Energy Astrophysical Phenomena · Physics 2015-06-24 Haocheng Zhang , Xuhui Chen , Markus Boettcher , Fan Guo , Hui Li

With their jet pointing towards us, blazars are ideal tools to study the physics and structure of extragalactic jets. Their powerful jets are cosmic particle accelerators and are alleged to be one of the production sites of the high-energy…

High Energy Astrophysical Phenomena · Physics 2025-11-25 Claudia M. Raiteri
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