Constraints on Blazar Jet Conditions During Gamma-Ray Flaring from Radiative Transfer Modeling
arXiv:1309.6614 · doi:10.1051/epjconf/20136107002
Abstract
As part of a program to investigate jet flow conditions during GeV gamma-ray flares detected by Fermi, we are using UMRAO multi-frequency, centimeter-band total flux density and linear polarization monitoring observations to constrain radiative transfer models incorporating propagating shocks orientated at an arbitrary angle to the flow direction. We describe the characteristics of the model, illustrate how the data are used to constrain the models, and present results for three program sources with diverse characteristics: PKS 0420-01, OJ 287, and 1156+295. The modeling of the observed spectral behavior yields information on the sense, strength and orientation of the shocks producing the radio-band flaring; on the energy distribution of the radiating particles; and on the observer's viewing angle with respect to the jet independent of VLBI data. We present evidence that, while a random component dominates the jet magnetic field, a distinguishing feature of those radio events with an associated gamma-ray flare is the presence of a weak but non-negligible ordered magnetic field component along the jet axis.
6 pages, 4 figures. To appear in the proceedings of "The Innermost Regions of Relativistic Jets and Their Magnetic Fields", Granada, Spain
References in corpus (8)
- Fermi Large Area Telescope Second Source Catalog
- MOJAVE: Monitoring of Jets in AGN with VLBA Experiments. V. Multi-epoch VLBA Images
- Gamma-Ray Studies of Blazars: Synchro-Compton Analysis of Flat Spectrum Radio Quasars
- Location of gamma-ray Flare Emission in the Jet of the BL Lacertae Object OJ287 more than 14pc from the Central Engine
- A Tight Connection between Gamma-Ray Outbursts and Parsec-Scale Jet Activity in the Quasar 3C 454.3
- Erratic Jet Wobbling in the BL Lacertae Object OJ287 Revealed by Sixteen Years of 7mm VLBA Observations
- The connection between gamma-ray emission and millimeter flares in Fermi/LAT blazars
- Oblique Shocks As The Origin Of Radio To Gamma-ray Variability In AGN