Physical Properties of Jets in AGN
arXiv:1110.4852 · doi:10.1142/S2010194512004552
Abstract
I review constraints on the physical properties of AGN jets revealed through Very Long Baseline Interferometry (VLBI) studies of the structure and time-evolution of parsec-scale jets, including recent results from the MOJAVE program. In particular I focus on constraints available from very long time baseline studies which probe a wide range of jet behavior over many outbursts. Kinematic studies of propagating jet features find an apparent speed distribution that peaks around 10c for blazars, with speeds up to 50c observed. These observed speeds require Lorentz factors at least as large, implying that parsec-scale Lorentz factors up to 10-20 are common for blazars with a tail up to ~ 50. Jet flows are still becoming organized on these scales as evidenced by the high incidence of non-radial motions and/or accelerations of jet features (including increases and decreases in apparent speed and direction). Changes in Lorentz factors of propagating jet features appear to play a significant role in the observed accelerations, and while the connection between acceleration of jet features and the underlying flow is not clear, the pattern of observed accelerations suggest the flow may increase in speed near the base of the jet and decrease further out. In some jets, ejections of new features span a range of ejection angles over many epochs, tracing out wider opening angles on parsec-scales than are apparent in single epoch observations.
10 pages, 2 figures, submitted to IJMPCS for proceedings of HEPROIII: High Energy Phenomena in Relativistic Outflows III, Barcelona, June 27 - July 1, 2011
References in corpus (10)
- Probing the Inner Jet of the Quasar PKS 1510-089 with Multi-waveband Monitoring during Strong Gamma-ray Activity
- Doppler factors, Lorentz factors and viewing angles for quasars, BL Lacertae objects and radio galaxies
- Sub-milliarcsecond Imaging of Quasars and Active Galactic Nuclei III. Kinematics of Parsec-Scale Radio Jets
- MOJAVE: Monitoring of Jets in AGN with VLBA Experiments. V. Multi-epoch VLBA Images
- Relativistic Beaming and the Intrinsic Properties of Extragalactic Radio Jets
- On the relation between AGN gamma-ray emission and parsec-scale radio jets
- The Jets of TeV Blazars at Higher Resolution: 43 GHz and Polarimetric VLBA Observations from 2005-2009
- A Multi-epoch VLBI Survey of the Kinematics of Caltech-Jodrell Bank Flat-Spectrum Sources, Part II: Analysis of the Kinematics
- Relativistic Jets in The Radio Reference Frame Image Database I: Apparent Speeds from the First Five Years of Data
- Oblique Shocks As The Origin Of Radio To Gamma-ray Variability In AGN