Multi-Epoch VLBA Observations of EGRET-Detected Quasars and BL Lac Objects: Superluminal Motion of Gamma-Ray Bright Blazars

Abstract

We present the results of a program to monitor the structure of the radio emission in 42 $\gamma$-ray bright blazars (31 quasars and 11 BL Lac objects) with the VLBA at 43, 22, and occasionally 15 and 8.4 GHz, over the period from November 1993 to July 1997. We determine proper motions in 33 sources and find that the apparent superluminal motions in $\gamma$-ray sources are much faster than for the general population of bright compact radio sources. This follows the strong dependence of the $\gamma$-ray flux on the level of relativistic beaming for both external-radiation Compton and synchrotron self-Compton emission. There is a positive correlation (correlation coefficient $r$=0.45) between the flux density of the VLBI core and the $\gamma$-ray flux and a moderate correlation (partial correlation coefficient $r$=0.31) between $\gamma$-ray apparent luminosity and superluminal velocities of jet components, as expected if the $\gamma$-ray emission originates in a very compact region of the relativistic jet and is highly beamed. In 43% of the sources the jet bends by more than 20${}^{\circ }$ on parsec scales, which is consistent with amplification by projection effects of modest actual changes in position angle. In 27 of the sources in the sample there is at least one non-core component that appears to be stationary during our observations. Different characteristics of stationary features close to and farther from the core lead us to suggest two different classes of stationary components: those within about 2 milliarcseconds (mas) of the core, probably associated with standing hydrodynamical compressions, and those farther down the jet, which tend to be associated with bends in the jet.

162 pages in ApJ (preprint) format, 9 tables, 48 figures, some of which have been bitmapped, accepted for publication in ApJS (v. 134)

Cited by in corpus (254)

• Leptonic and Hadronic Modeling of Fermi-Detected Blazars
• Polarimetric Observations of 15 Active Galactic Nuclei at High Frequencies: Jet Kinematics from Bimonthly Monitoring with the Very Long Baseline Array
• General Relativistic Magnetohydrodynamic Simulations of Jet Formation and Large-Scale Propagation from Black Hole Accretion Systems
• Doppler factors, Lorentz factors and viewing angles for quasars, BL Lacertae objects and radio galaxies
• Bright AGN Source List from the First Three Months of the Fermi Large Area Telescope All-Sky Survey
• Sub-milliarcsecond Imaging of Quasars and Active Galactic Nuclei III. Kinematics of Parsec-Scale Radio Jets
• GRS 1915+105 and the Disc-Jet Coupling in Accreting Black Hole Systems
• Sub-milliarcsecond Imaging of Quasars and Active Galactic Nuclei. IV. Fine Scale Structure
• Magnetic acceleration of relativistic AGN jets
• Constraining Emission Models of Luminous Blazar Sources
• Kinematics of Parsec-Scale Jets of Gamma-Ray Blazars at 43~GHz within the VLBA-BU-BLAZAR Program
• MOJAVE: Monitoring of Jets in AGN with VLBA Experiments - I. First-Epoch 15 GHz Linear Polarization Images
• The Fermi blazar sequence
• Total and Jet Blandford-Znajek Power in Presence of Accretion Disk
• A Black Hole in the Superluminal source SAX J1819.3-2525 (V4641 Sgr)
• Magnetic Driving of Relativistic Outflows in Active Galactic Nuclei. I. Interpretation of Parsec-Scale Accelerations
• Relativistic Magnetohydrodynamics with Application to Gamma-Ray Burst Outflows: I. Theory and Semianalytic Trans-Alfvenic Solutions
• Relativistic beaming and gamma-ray brightness of blazars
• Decelerating Flows in TeV Blazars: A Resolution to the BL Lac -- FR I Unification Problem
• Optical and radio behaviour of the BL Lacertae object 0716+714
• Location of gamma-ray Flare Emission in the Jet of the BL Lacertae Object OJ287 more than 14pc from the Central Engine
• From the Blazar Sequence to the Blazar Envelope: Revisiting the Relativistic Jet Dichotomy in Radio-loud AGN
• Optical and radio variability of the BL Lac object AO 0235+16: a possible 5-6 year periodicity
• The dividing line between FR I and FR II radio--galaxies
• A Tight Connection between Gamma-Ray Outbursts and Parsec-Scale Jet Activity in the Quasar 3C 454.3
• Multi-Epoch VLBA Observations of EGRET-Detected Quasars and BL Lac Objects: Connection between Superluminal Ejections and Gamma-Ray Flares in Blazars
• Multiwaveband Polarimetric Observations of 15 Active Galactic Nuclei at High Frequencies: Correlated Polarization Behavior
• Dynamics and High Energy Emission of the Flaring HST-1 Knot in the M 87 Jet
• Synchrotron Self-Compton Model for Rapid Nonthermal Flares in Blazars with Frequency-Dependent Time Lags
• An ultra-relativistic outflow from a neutron star accreting gas from a companion
• Are quasar jets dominated by Poynting flux?
• The Blazar Main Sequence
• Results of WEBT, VLBA and RXTE monitoring of 3C 279 during 2006-2007
• Kinematics of Parsec-Scale Jets of Gamma-Ray Bright Blazars at 43 GHz during Ten Years of the VLBA-BU-BLAZAR Program
• Shear acceleration in relativistic astrophysical jets
• A View through Faraday's Fog 2: Parsec Scale Rotation Measures in 40 AGN
• The Outburst of the Blazar S5 0716+71 in 2011 October: Shock in a Helical Jet
• The Parsec-Scale Structure and Jet Motions of the TeV Blazars 1ES 1959+650, PKS 2155-304, and 1ES 2344+514
• On the Location of the Gamma-ray Emission in the 2008 Outburst in the BL Lacertae Object AO 0235+164 through Observations across the Electromagnetic Spectrum
• Rapid TeV variability in Blazars as result of Jet-Star Interaction
• Gamma-Ray and Parsec-Scale Jet Properties of a Complete Sample of Blazars From the MOJAVE Program
• A supermassive binary black hole in the quasar 3C345
• First Results from MASIV: The Micro-Arcsecond Scintillation-Induced Variability Survey
• Chandra Discovery of a 300 kpc X-ray Jet in the GPS Quasar PKS1127-145
• A Connection Between Apparent VLBA Jet Speeds and Initial Active Galactic Nucleus Detections Made by the Fermi Gamma-ray Observatory
• Pearson-Readhead Survey Sources II: The Longterm Centimeter-band Total Flux and Linear Polarization Properties of a Complete Radio Sample
• Opening angles, Lorentz factors and confinement of X-ray binary jets
• Helical jets in blazars. Interpretation of the multifrequency long-term variability of AO 0235+16
• Connecting radio variability to the characteristics of gamma-ray blazars
• 3C454.3 reveals the structure and physics of its 'blazar zone'
• Recollimation and Radiative Focusing of Relativistic Jets: Applications to Blazars and M87
• Fermi Large Area Telescope Detection of Bright Gamma-ray Outbursts from a Peculiar Quasar 4C +21.35
• Erratic Jet Wobbling in the BL Lacertae Object OJ287 Revealed by Sixteen Years of 7mm VLBA Observations
• A View through Faraday's fog: Parsec scale rotation measures in AGN
• The Outburst of the Blazar AO 0235+164 in 2006 December: Shock-in-Jet Interpretation
• A Sample of Low Redshift BL Lacs. I. The Radio Data
• TANAMI monitoring of Centaurus A: The complex dynamics in the inner parsec of an extragalactic jet
• Testing the inverse-Compton catastrophe scenario in the intra-day variable blazar S5 0716+71, III. Rapid and correlated flux density variability from radio to sub-mm bands
• Radio observations of active galactic nuclei with mm-VLBI
• Relativistic Outflow Drives Gamma-Ray Emission in 3C345
• A Multi-epoch VLBI Survey of the Kinematics of Caltech-Jodrell Bank Flat-Spectrum Sources, Part II: Analysis of the Kinematics
• Probing Acceleration and Turbulence at Relativistic Shocks in Blazar Jets
• The Parsec-Scale Jets of the TeV Blazars H 1426+428, 1ES 1959+650, and PKS 2155-304: 2001-2004
• Statistics of Cosmological Black Hole Jet Sources: Blazar Predictions for GLAST
• Relativistic Jets in the Radio Reference Frame Image Database II: Blazar Jet Accelerations from the First 10 Years of Data (1994 - 2003)
• VLBI observations of 10 CSO candidates: expansion velocities of hot spots
• 4C +12.50: A Superluminal Precessing Jet in the Recent Merger System IRAS 13451+1232
• A multi-wavelength polarimetric study of the blazar CTA 102 during a Gamma-ray flare in 2012
• Testing the inverse-Compton catastrophe scenario in the intra-day variable blazar S5 0716+71. I. Simultaneous broadband observations during November 2003
• Kinematic Study of the Blazar S5 0716+714
• Uses and limitations of relativistic jet proper motions: lessons from galactic microquasars
• 3D Hydrodynamic Simulations of Relativistic Extragalactic Jets
• Multifrequency variability of the blazar AO 0235+164. The WEBT campaign in 2004-2005 and long-term SED analysis
• Relativistic Jets in The Radio Reference Frame Image Database I: Apparent Speeds from the First Five Years of Data
• Multifrequency VLBA Monitoring of 3C 273 during the INTEGRAL Campaign in 2003 - I. Kinematics of the Parsec Scale Jet from 43 GHz Data
• Radio and gamma-ray follow-up of the exceptionally high activity state of PKS 1510-089 in 2011
• A 3.5mm Polarimetric Survey of Radio-loud Active Galactic Nuclei
• Multi-wavelength observations of blazar AO 0235+164 in the 2008-2009 flaring state
• Fermi-LAT observations of the exceptional gamma-ray outbursts of 3C 273 in September 2009
• Locating the gamma-ray emission site in Fermi/LAT blazars from correlation analysis between 37 GHz radio and gamma-ray light curves
• Observational evidence for the link between the variable optical continuum and the subparsec-scale jet of the radio galaxy 3C 390.3
• Multifrequency Photo-polarimetric WEBT Observation Campaign on the Blazar S5 0716+714: Source Microvariability and Search for Characteristic Timescales
• Rapid Multiwaveband Polarization Variability in the Quasar PKS 0420-014: Optical Emission from the Compact Radio Jet
• Calibration of ALMA as a phased array: ALMA observations during the 2017 VLBI campaign
• Radio and $\gamma$-ray variability in the BL Lac PKS 0219 -164: Detection of quasi-periodic oscillations in the radio light curve
• Characteristics of Gamma-Ray Loud Blazars in the VLBA Imaging and Polarimetry Survey
• Multiwavelength Observations of 3C 66A during the WEBT campaign of 2003 - 2004
• Hydrodynamic Collimation of Relativistic Outflows: Semianalytic Solutions and Application to Gamma-Ray Bursts
• The Highly Relativistic Kiloparsec-Scale Jet of the Gamma-Ray Quasar 0827+243
• POLAMI: Polarimetric Monitoring of Active Galactic Nuclei at Millimetre Wavelengths. II. Widespread circular polarisation
• Multi-color Near Infra-red Intra-day and Short Term Variability of the Blazar S5 0716+714
• The Relativistic Jet Dichotomy and the End of the Blazar Sequence
• Doppler Boosting, Superluminal Motion, and the Kinematics of AGN Jets
• Multiwavelength behaviour of the blazar 3C279: decade-long study from $\gamma$-ray to radio
• Observations of the BL Lac Object 3C 66A with STACEE
• The Megaparsec-Scale X-ray Jet of the BL Lac Object OJ287
• Frequency and Time Dependence of Linear Polarization in Turbulent Jets of Blazars
• Constraints on Lorentz Invariance Violating Quantum Gravity and Large Extra Dimensions Models using High Energy Gamma Ray Observations
• The WEBT campaign to observe AO 0235+16 in the 2003-2004 observing season
• Synchronous Optical and Radio Polarization Variability in the Blazar OJ287
• New constraints on the structure and dynamics of black hole jets
• The Sub-Luminal Parsec-scale Jet of Mkn 501
• rHARM: Accretion and Ejection in Resistive GR-MHD
• The Disc-Jet Relation in Strong-Lined Blazars
• Cosmic Physics: The High Energy Frontier
• Collective Evidence for Inverse Compton Emission from External Photons in High-Power Blazars
• The WEBT Campaign on the Intermediate BL Lac Object 3C66A in 2007-2008
• On the Origin of Rapid Flares in TeV Blazars
• Multifrequency Studies of the Peculiar Quasar 4C +21.35 During the 2010 Flaring Activity
• Chandra Reveals Twin X-ray Jets in the Powerful FR-II Radio Galaxy 3C353
• VLBA Polarization Observations of Markarian 421 After a Gamma-Ray High State
• Fermi Gamma-ray Space Telescope: High-Energy Results from the First Year
• PKS 1510-089: A Head-On View of a Relativistic Jet
• The Outburst of the Blazar S40954+658 in March-April 2011
• Milli-arcsecond--scale Spectral Properties and Jet Motions in M87
• Two Flares with One Shock: the Interesting Case of 3C 454.3
• Radiation from relativistic jets in blazars and the efficient dissipation of their bulk energy via photon breeding
• Lorentz Factors of compact jets in Black hole X-ray binaries
• The bulk kinetic power of radio jets in active galactic nuclei
• Characteristics of EGRET Blazars in the VLBA Imaging and Polarimetry Survey (VIPS)
• Multi-frequency monitoring of gamma-ray loud blazars: I. Light curves and spectral energy distributions
• Optical polarization angle and VLBI jet direction in the binary black hole model of OJ287
• Wavelet analysis of a large sample of AGN at high radio frequencies
• High-Energy Aspects of Astrophysical Jets
• Intraday Variability in Northern Hemisphere Radio Sources
• Fine-scale structure of the quasar 3C 279 Measured with 1.3 mm very long baseline interferometry
• Multiwavelength variability and correlation studies of Mrk 421 during historically low X-ray and $\gamma$-ray activity in 2015$-$2016
• Significant Limb-Brightening in the Inner Parsec of Markarian 501
• Synchrotron and inverse-Compton emission from blazar jets - III. Compton-dominant blazars
• Short-Term Radio Variability and Parsec-Scale Structure in a Gamma-Ray Narrow-Line Seyfert 1 Galaxy 1H 0323+342
• Quasi-Periodic Oscillations in the long term radio light curves of the blazar AO 0235+164
• The Trails of Superluminal Jet Components in 3C111
• Jet Parameters in the Black-Hole X-Ray Binary MAXI J1820+070
• Spectroscopic monitoring of the BL Lac object AO 0235+164
• Multiwavelength Observations of the Gamma-Ray Blazar PKS 0528+134 in Quiescence
• Dual frequency VSOP imaging of the jet in S5 0836+710
• Rapid optical variability of TeV blazars
• A relativistic helical jet in the gamma-ray AGN 1156+295
• A test on external Compton models for $\gamma$-ray active galactic nuclei
• X-ray emission from the blazar AO 0235+16: the XMM-Newton and Chandra point of view
• The Fastest Relativistic Jets: VLBA Observations of Blazars with Apparent Speeds Exceeding 25c
• Basic properties of Fermi blazars and the "blazar sequence"
• An optical overview of blazars with LAMOST I: Hunting changing-look blazars and new redshift estimates
• Swift observations of IBL and LBL objects
• Observation of a sudden cessation of a very-high-energy gamma-ray flare in PKS 1510-089 with H.E.S.S. and MAGIC in May 2016
• Fermi-Large Area Telescope observations of the brightest Gamma-ray flare ever detected from CTA 102
• Radio structure of the blazar 1156+295 with sub-pc resolution
• The extreme blazar AO 0235+164 as seen by extensive ground and space radio observations
• The Estimation of Fundamental Physics Parameters for Fermi-LAT Blazars
• Day-timescale variability in the radio light curve of the Tidal Disruption Event AT2022cmc: confirmation of a highly relativistic outflow
• A Multi-Epoch VLBI Survey of the Kinematics of CJF Sources; Part I: Model-Fit Parameters and Maps
• Optical Monitoring of PKS 1510-089: A Binary Black Hole System?
• An HST Proper-Motion Study of the Large-scale Jet of 3C273
• The connection between the parsec-scale radio jet and gamma-ray flares in the blazar 1156+295
• Do the mildly superluminal VLBI knots exclude ultrarelativistic blazar jets?
• The Duty-cycle of Gamma-ray Blazars: a New Approach, New Results
• Non-radial motion in the TeV blazar S5 0716+714 The pc-scale kinematics of a BL Lac Object
• Parsec-scale jet properties of the gamma-ray quasar 3C 286
• VLBA polarimetric monitoring of 3C 111
• The June 2016 Optical and Gamma-Ray Outburst and Optical Micro-Variability of the Blazar 3C454.3
• Parameter constraints in a near-equipartition model with multi-frequency \emph{NuSTAR}, \emph{Swift} and \emph{Fermi-LAT} data from 3C 279
• Determination of Central Engine Position and Accretion Disk Structure in NGC 4261 by Core Shift Measurements
• High Frequency Gravitational Waves from Supermassive Black Holes: Prospects for LIGO-Virgo Detections
• Multi-color optical monitoring of ten blazars from 2005 to 2011
• Exploring the multiband emission of TXS 0536+145: the most distant gamma-ray flaring blazar
• Multi-epoch parsec-scale observations of the blazar PKS 1510-089
• Variability and Spectral Characteristics of Three Flaring Gamma-ray Quasars Observed by VERITAS and Fermi-LAT
• Orphan γ-ray flares from relativistic blobs encountering luminous stars
• Simultaneous X-ray and infrared variability in the quasar 3C273 II: Confirmation of the correlation and X-ray lag
• [O I] 63 micron Emission from High and Low Luminosity AGN Galaxies
• Intra-Night Optical monitoring of three γ-ray detected Narrow-line Seyfert 1 galaxies
• The Variability and Period Analysis for the BL Lac AO 0235+164
• Lorentz factor distribution of blazars from the optical Fundamental plane of black hole activity
• VLBI for Gravity Probe B: The Guide Star IM Pegasi
• Core shift effect in blazars
• Magnetic acceleration of ultra-relativistic GRB and AGN jets
• Serendipitous VLBI detection of rapid, large-amplitude, intraday variability in QSO 1156+295
• Discovery of Optical Emission in the Hotspots of Three 3CR Quasars: High-Energy Particle Acceleration in Powerful Radio Hotspots
• The high energy spectrum of 3C 273
• High Resolution Radio Astronomy Using Very Long Baseline Interferometry
• Bulk Motion of Ultrarelativistic Conical Blazar Jets
• Imaging and variability studies of CTA~102 during the 2016 January $\gamma$-ray flare
• Frequency dependent core shifts and parameter estimation for the blazar 3C 454.3
• Relativistic Beaming and Flux Variability in Active Galactic Nuclei
• Blazar 3C 454.3 in Outburst and Quiescence During 2005-2007: Two Variable Synchrotron Emission Peaks
• High-frequency very long baseline interferometry studies of NRAO 530
• Constraints on the location of $\gamma$-ray emitting region for a sample of blazars with radio core-shift measurements
• Why are some BL Lacs detected by \fermi, but others not ?
• Constraints on Electron Acceleration in Gamma-Ray Bursts Afterglows from Radio Peaks
• Jet Kinematics of the Quasar 4C +21.35 from Observations with the KaVA Very Long Baseline Interferometry Array
• X-Ray Emission from the Quasar PKS 1127-145: Comptonized IR Photons on Parsec Scales
• A kinematic study of the compact jet in quasar B3 1633+382
• First-generation Science Cases for Ground-based Terahertz Telescopes
• TANAMI: Tracking Active Galactic Nuclei with Austral Milliarcsecond Interferometry - II. Additional Sources
• Gamma-Ray Burst Afterglows as Analogues of High Frequency-Peaked BL Lac Objects
• Optical Quasi-periodic Oscillations in the TESS light curves of three blazars
• The Relation between Radio Polarization and Gamma-ray Emission in AGN Jets
• A Method for Locating High Energy Dissipation Region in Blazar
• Optical flux behaviour of a sample of Fermi blazars
• Multi-Frequency VLBI Observations of NRAO 530
• The parsec-scale jet of PKS 1749+096
• The $\gamma$-ray sky seen at X-ray energies I. Searching for the connection between X-rays and $\gamma$-rays in Fermi BL Lac objects
• The beaming effect and $\gamma$-ray emission for Fermi blazars
• Multi-frequency VLBA study of the blazar S5 0716+714 during the active state in 2004: I. Inner jet kinematics
• Radio follow-up of the gamma-ray flaring gravitational lens JVAS B0218+357
• A search for periodicity in the light curves of selected blazars
• Exploring the Nature of the 2016 γ-ray Emission in the Blazar 1749+096
• Origin of X-rays in the low state of the FSRQ 3C 273: Evidence of inverse Compton emission
• On the significance of relativistically hot pairs in the jets of FR II radio galaxies
• VLBI for Gravity Probe B. III. A Limit on the Proper Motion of the "Core" of the Quasar 3C 454.3
• The Intrinsic $\gamma$-ray Emissions of $Fermi$ Blazars
• Multi-epoch VLBA observations of 3C 66A
• Blazar Sheath Illumination of the Outer Molecular Torus: A Resolution of the Seed Photon Problem for the far-GeV Blazar flares
• Extreme Superluminal Motion in the Curved Jet of PKS 1502+106
• X-ray Intraday Variability and Power Spectral Density Profiles of the Blazar 3C 273 with XMM-Newton during 2000-2021
• Multi-waveband polarimetric observations of NRAO 530 on parsec-scale
• Multiwavelength variability of the blazar AO 0235+164
• VLBI for Gravity Probe B. II. Monitoring of the Structure of the Reference Sources 3C 454.3, B2250+194, and B2252+172
• Catching profound optical flares in blazars
• Detecting the Elusive Blazar Counter-Jets
• Exploring the bulk of the BL Lac object population:1. parsec-scale radio structures
• Multi-wavelength Variation Phenomena of PKS 0735+178 on Diverse Timescale
• VSOP monitoring of the compact BL Lac object AO 0235+164
• On leptonic models for blazars in the Fermi era
• Tests of Quantum Gravity and Large Extra Dimensions Models Using High Energy Gamma Ray Observations
• The Repeating Flaring Activity of Blazar AO 0235+164
• A sample of weak blazars at milli-arcsecond resolution
• Collimation and Radiative Deceleration of Jets in TeV AGNs
• Superluminal apparent motions in distant radio sources
• Mechanism of very high energy radiation in BL Lacertae object 3C 66A
• Gamma-ray emission region located in the parsec scale jet of OJ287
• Gamma-ray-emitting quasar 0202$+$149: a CSS revisited
• PKS 1622-253: A Weakly Accreting, Powerful Gamma Ray Source
• Observations of Lensed Relativistic Jets as a Tool of Constraining Lens Galaxy Parameters
• The Velocity Field of Quasar Broad Emission Line Gas
• Multi-epoch, multi-frequency VLBI study of the parsec-scale jet in the blazar 3C 66A
• A Systematic Search for Spectral Hardening in Blazar Flares with the Fermi-Large Area Telescope
• Milliarcsecond-Scale Structure in the Gamma-Ray Loud Quasar PKS 1622-297
• Linear Polarization as a Probe of Gamma Ray Flaring Blazar Jets
• Proper Motions in the sub-kiloparsec Jet of 3C 78: Novel Constraints on the Physical Nature of Relativistic Jets
• Millimeter-wave Monitoring of Active Galactic Nuclei with the Africa Millimetre Telescope
• Multi-band optical variability on diverse timescales of blazar 1E 1458.8+2249
• Kinematics of AGN Jets
• Tension of toroidal magnetic field in reconnection plasmoids and relativistic jets
• VLBI Monitoring of the Sub-parsec-scale Jet in the Radio Galaxy 3C 66B at 22 GHz
• Rapid jet ejection from PKS 0215+015 coincident with a high-energy neutrino event
• On the connection between radio and gamma rays. Variability and polarization properties in relativistic jets
• Astrophysics at the Highest Energy Frontiers
• Ultimate synchrotron cutoff in gamma-ray spectra of blazars as a signature of the converter mechanism
• Multi-Band Optical Variability of Blazar 1ES 2344+514 on Diverse Time-Scales
• The blazar sequence revised
• Apparent superluminal velocities and random walk in the velocity space
• Applying Relativistic Reconnection to Blazar Jets
• A possible feature of thermal matter in relativistic jets of radio-loud quasars