Optical Polarimetric and Multiwavelength Flaring Activity of Blazar 3C 279

Abstract

Abstract An exhaustive analysis of 9 yr optical R-band photopolarimetric data of the flat-spectrum radio quasar 3C 279 from 2008 February 27 to 2017 May 25 is presented, along with multiwavelength observing campaigns performed during the flaring activity exhibited in 2009 February/March, 2011 June, 2014 March/April, 2015 June, and 2017 February. In the R band, this source showed the maximum brightness state of 13.68 ± 0.11 mag (1.36 ± 0.20 mJy) on 2017 March 2 and the lowest brightness state ever recorded of 18.20 ± 0.87 mag (0.16 ± 0.03 mJy) on 2010 June 17. During the entire period of observations, the polarization degree varied between 0.48% ± 0.17% and 31.65% ± 0.77%, and the electric vector position angle (EVPA) exhibited large rotations between 82.°98 ± 0.°92 and 446.°32 ± 1.°95. Optical polarization data show that this source has a stable polarized component that varied from ∼6% (before the 2009 flare) to ∼13% after the flare. The overall behavior of our polarized variability data supports the scenario of jet precessions as responsible for the observed large rotations of the EVPA. Discrete correlation function analysis shows that the lags between gamma-rays and X-rays compared to the optical R-band fluxes are Δt ∼ 31 days and 1 day in 2009. Lags were also found among gamma-rays compared with X-rays and radio of Δt ∼ 30 and 43 days in 2011, and among radio and optical R band of Δt ∼ 10 days in 2014. A very intense flare in 2017 was observed in optical bands, with a dramatic variation in the polarization degree (from ∼6% to 20%) in 90 days without exhibiting flaring activity in other wavelengths.