Related papers: Study of correlation between optical flux and pola…
Study of the polarization behaviour in blazars is a powerful tool to discern the role of magnetic field in the variable emission process in their relativistic jets. We present here results of our systematic investigation on the correlation…
Due to the first results on astrophysical X-ray polarization provided by \textit{IXPE} observatory, the interest in wavelength-dependent synchrotron polarization of BL Lac type objects increases. This paper presents the results of…
We present a polarization variability analysis of a sample of 26 $\gamma$-ray blazars monitored by the Steward Observatory between 2008 and 2018 in the optical band. We investigate the properties and long-term variability of their optical…
We report on the correlation between the flux, color and polarization variations on time scales of days--months in blazars, and discuss their universal aspects. We performed monitoring of 42 blazars in the optical and near-infrared bands…
We present an analysis of the cross-correlation between optical brightness and polarization degree in different types of blazars. The aim is to identify objects with simultaneous and consistent changes in characteristics and to determine if…
We present the results of flux density, spectral index, and polarization intra-night monitoring studies of a sample of eight optically bright blazars, carried out by employing several small to moderate aperture (0.4\,m to 1.5\,m diameter)…
Blazars show optical and $\gamma$-ray flux variations that are generally correlated, although there are exceptions. Here we present anomalous behaviour seen in the blazar 3C 454.3 based on an analysis of quasi-simultaneous data at optical,…
The correlation between optical and $\gamma$-ray flux variations in blazars reveals a complex behaviour. In this study, we present our analysis of the connection between changes in optical and $\gamma$-ray emissions in the blazar Ton 599…
We explore the variability and cross-frequency correlation of the flux density and polarization of the blazar OJ287, using imaging at 43 GHz with the Very Long Baseline Array, as well as optical and near-infrared polarimetry. The…
A high degree of linear polarization measured in the optical emission is an important observational feature of blazars. It provides strong evidence of the presence of relativistic particles and magnetic field ordering in the non-thermal…
We report on the variation in the optical polarization of the blazar PKS 1749+096 observed in 2008--2015. The degree of polarization (PD) tends to increase in short flares having a time-scale of a few days. The object favors a polarization…
We have measured multi-band optical flux and colour variations for a sample of 12 low energy peaked blazars on short, day-to-month, timescales. Our sample contains six BL Lacertae objects and six flat spectrum radio quasars. These…
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…
We present the results of photometric (V band) and polarimetric observations of the blazar BL Lac during 2008--2010 using TRISPEC attached to the KANATA 1.5-m telescope in Japan. The data reveal a great deal of variability ranging from days…
In this paper, we explore the behavior of optical polarization during the multi-wavelength outburst of the blazar Mrk 421 detected in February 2010. We use optical polarization measurements in the wavelength range 500-700 nm from SPOL…
Aims. We aim to investigate the extreme variability properties of the TeV blazar S4 0954+65 using optical photometric and polarisation observations carried out between 2017 and 2023 using three ground-based telescopes. Methods. We examined…
The variation mechanism of blazars is a long standing open question. The polarization observation can provide us with more information to constrain models. In this work, we collect the long term multi-wavelength data of AO 0235+164, and…
We report on long-term multi-wavelength monitoring of blazar Mrk 421 by the GASP-WEBT collaboration and Steward Observatory, and by the Swift and Fermi satellites. We study the source behaviour in the period 2007-2015, characterized by…
An analysis is presented of the optical polarimetric and multicolour photometric ($BVRJ$) behaviour of the blazar PKS 2155$-$304 during an outburst in 2010. This flare develops over roughly 117 days, with a flux doubling time $\tau \sim 11$…
The results of 8-year R-band photopolarimetric data of blazar Mrk 421 collected from February 2008 to May 2016 are presented, along with extensive multiwavelength observations covering from radio to TeV $\gamma$-rays around the flares…