Parsec-Scale Behavior of Blazars during High Gamma-Ray States

Abstract

We compare the γ-ray light curves of the blazars, constructed with data provided by the Fermi Large Area Telescope, with flux and polarization variations in the VLBI core and bright superluminal knots obtained via monthly monitoring with the Very Long Baseline Array at 43 GHz. For all blazars in the sample that exhibit a high γ-ray state on time scales from several weeks to several months, an increase of the total flux in the mm-wave core is contemporaneous with the γ-ray activity (more than a third of the sample). Here we present the results for quasars with the most extreme γ-ray behavior (3C 454.3, 3C 273, 3C 279, 1222+216, and 1633+382). The sources show that in addition to the total flux intensity behavior, a maximum in the degree of polarization in the core or bright superluminal knot nearest to the core coincides with the time of a γ-ray peak to within the accuracy of the sampling of the radio data. These argue in favor of location of many of γ-ray outbursts in blazars outside of the broad line region, either in the vicinity or downstream of the mm-wave VLBI core.

2011 Fermi Symposium proceedings - eConf C110509

References in corpus (3)

• Location of gamma-ray Flare Emission in the Jet of the BL Lacertae Object OJ287 more than 14pc from the Central Engine
• The multiwavelength variability of 3C 273
• Fermi-LAT observations of the exceptional gamma-ray outbursts of 3C 273 in September 2009

Cited by in corpus (7)

• Constraining the location of rapid gamma-ray flares in the FSRQ 3C 273
• A connection between $\gamma$-ray and parsec-scale radio flares in the blazar 3C 273
• Exploring the nature of broadband variability in the FSRQ 3C 273
• Planck intermediate results. XLV. Radio spectra of northern extragalactic radio sources
• 3C273 variability at 7 mm: Evidences of shocks and precession in the jet
• Diversity of gamma-ray and Radio Variabilities of Bright Blazars and Implications for gamma-ray Emission Location
• Galaxies as High-Resolution Telescopes