Contemporaneous VLBA 5 GHz Observations of LAT-Detected Blazars

Abstract

The radio properties of blazars detected by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope have been observed contemporaneously by the Very Long Baseline Array (VLBA). In total, 232 sources were observed with the VLBA. Ninety sources that were previously observed as part of the VLBA Imaging and Polarimetry Survey (VIPS) have been included in the sample, as well as 142 sources not found in VIPS. This very large, flux-limited sample of active galactic nuclei (AGN) provides insights into the mechanism that produces strong gamma-ray emission. In particular, we see that gamma-ray emission is related to strong, uniform magnetic fields in the cores of the host AGN. Included in this sample are non-blazar AGN such as 3C84, M82, and NGC 6251. For the blazars, the total VLBA radio flux density at 5 GHz correlates strongly with gamma-ray flux. The LAT BL Lac objects tend to be similar to the non-LAT BL Lac objects, but the LAT flat-spectrum radio quasars (FSRQs) are significantly different from the non-LAT FSRQs. Strong core polarization is significantly more common among the LAT sources, and core fractional polarization appears to increase during LAT detection.

arXiv comment47 pages, 12 figures, accepted for publication in The Astrophysical Journal

References in corpus (50)

• Unified Schemes for Radio-Loud Active Galactic Nuclei
• The Large Area Telescope on the Fermi Gamma-ray Space Telescope Mission
• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Data Processing, Sky Maps, and Basic Results
• The Sixth Data Release of the Sloan Digital Sky Survey
• Fermi Large Area Telescope First Source Catalog
• The Third Data Release of the Sloan Digital Sky Survey
• MOJAVE: Monitoring of Jets in Active Galactic Nuclei with VLBA Experiments. VI. Kinematics Analysis of a Complete Sample of Blazar Jets
• DiFX2: A more flexible, efficient, robust and powerful software correlator
• Probing the Inner Jet of the Quasar PKS 1510-089 with Multi-waveband Monitoring during Strong Gamma-ray Activity
• CRATES: An All-Sky Survey of Flat-Spectrum Radio Sources
• The First Catalog of Active Galactic Nuclei Detected by the Fermi Large Area Telescope
• Bright AGN Source List from the First Three Months of the Fermi Large Area Telescope All-Sky Survey
• MOJAVE: Monitoring of Jets in AGN with VLBA Experiments. V. Multi-epoch VLBA Images
• Sub-milliarcsecond Imaging of Quasars and Active Galactic Nuclei. IV. Fine Scale Structure
• Gamma-ray Light Curves and Variability of Bright Fermi-Detected Blazars
• A change in the optical polarization associated with a gamma-ray flare in the blazar 3C 279
• Radio-Loud Narrow-Line Seyfert 1 as a New Class of Gamma-Ray AGN
• CGRaBS: An All-Sky Survey of Gamma-Ray Blazar Candidates
• Jet opening angles and gamma-ray brightness of AGN
• Relativistic beaming and gamma-ray brightness of blazars
• The VLBA Imaging and Polarimetry Survey at 5 GHz
• Flaring Behavior of the Quasar 3C~454.3 across the Electromagnetic Spectrum
• Unabsorbed Seyfert 2 galaxies
• On the relation between AGN gamma-ray emission and parsec-scale radio jets
• VLBA Absorption Imaging of Ionized Gas Associated with the Accretion Disk in NGC 1275
• On the origin of the gamma-ray emission from the flaring blazar PKS 1222+216
• A narrow line Seyfert 1--blazar composite nucleus in 2MASX J0324+3410
• On the Evolution of and High-Energy Emission from GHz-Peaked-Spectrum Sources
• Gamma-Ray and Parsec-Scale Jet Properties of a Complete Sample of Blazars From the MOJAVE Program
• MOJAVE: Monitoring of Jets in AGN with VLBA Experiments. VII. Blazar Jet Acceleration
• Magnetic Fields in the Center of the Perseus Cluster
• The colour of the narrow line Sy1-blazar 0324+3410
• TANAMI: Tracking Active Galactic Nuclei with Austral Milliarcsecond Interferometry I. First-Epoch 8.4 GHz Images
• The Gamma-Ray Blazar Content of the Northern Sky
• A Connection Between Apparent VLBA Jet Speeds and Initial Active Galactic Nucleus Detections Made by the Fermi Gamma-ray Observatory
• A Multi-epoch VLBI Survey of the Kinematics of Caltech-Jodrell Bank Flat-Spectrum Sources, Part II: Analysis of the Kinematics
• A Large Sample of BL Lacs from SDSS and FIRST
• A 3.5mm Polarimetric Survey of Radio-loud Active Galactic Nuclei
• The first Fermi multifrequency campaign on BL Lacertae: characterizing the low-activity state of the eponymous blazar
• Magnetically-Dominated Accretion Flows (MDAFs) and Jet Production in the Low/Hard STate
• Hubble Space Telescope ACS mosaic of the prototypical starburst galaxy M82
• Characteristics of Gamma-Ray Loud Blazars in the VLBA Imaging and Polarimetry Survey
• Discovery of mHz X-ray Oscillations in a Transient Ultraluminous X-ray Source in M82
• Characteristics of EGRET Blazars in the VLBA Imaging and Polarimetry Survey (VIPS)
• The soft X-ray properties of AGN from the CJF sample; A correlation analysis between soft X-ray and VLBI properties
• VLBA Imaging Polarimetry of Active Galactic Nuclei - An Automated Approach
• The Radio to Gamma Ray Connection of EGRET Blazars: Correlation, Regression and Monte Carlo Analysis
• The Connection between Radio and Gamma-ray Emission in Active Galactic Nuclei
• Multiple inverse Compton scatterings and the blazar sequence
• A Statistical Description of AGN Jet Evolution from the VLBA Imaging and Polarimetry Survey (VIPS)

Cited by in corpus (39)

• MOJAVE XIII. Parsec-Scale AGN Jet Kinematics Analysis Based on 19 years of VLBA Observations at 15 GHz
• Connecting radio variability to the characteristics of gamma-ray blazars
• Optical spectroscopic observations of gamma-ray blazars candidates I: preliminary results
• Unveiling the nature of the unidentified gamma-ray sources III: gamma-ray blazar-like counterparts at low radio frequencies
• The Radio Fundamental Catalogue. I. Astrometry
• First-Epoch VLBA Imaging of Twenty New TeV Blazars
• MOJAVE XVI: Multi-Epoch Linear Polarization Properties of Parsec-Scale AGN Jet Cores
• Short-Term Radio Variability and Parsec-Scale Structure in a Gamma-Ray Narrow-Line Seyfert 1 Galaxy 1H 0323+342
• VERITAS detection of $\gamma$-ray flaring activity from the BL Lac object 1ES 1727+502 during bright moonlight observations
• Search for anisotropic Lorentz invariance violation with γ-rays
• Investigating the peculiar emission from the new VHE gamma-ray source H1722+119
• Basic properties of Fermi blazars and the "blazar sequence"
• Quasar-driven outflows account for the missing extragalactic gamma-ray background
• Exploring the relation between (sub-)millimeter radiation and gamma-ray emission in blazars with Planck and Fermi
• The High Redshift Blazar S5 0836+71: A Broadband Study
• SDSS J094635.06+101706.1: a redshift one, very radio-loud, γ-ray emitting narrow-line Seyfert 1 galaxy
• HESS J1943+213: An Extreme Blazar Shining Through The Galactic Plane
• Why are some BL Lacs detected by \fermi, but others not ?
• Gamma-ray Loudness, Synchrotron Peak Frequency, and Parsec-Scale Properties of Blazars Detected by the Fermi Large Area Telescope
• Rapid high-amplitude gamma-ray variability in Blazar PKS 0507+17
• Constraints on the location of the gamma-ray emission region for the gamma-ray-loud radio source GB 1310+487
• What determines the observational differences of blazars?
• TXS 1206+549: a new $\gamma$-ray detected narrow-line Seyfert 1 galaxy at redshift 1.34?
• Variability of GeV gamma-ray emission in QSO B0218+357 due to microlensing on intermediate size structures
• The Most Compact Bright Radio-loud AGN -- II. VLBA Observations of Ten Sources at 43 and 86~GHz
• Optical variability of a newly discovered blazar sample from the BZCAT Catalog
• A sample of weak blazars at milli-arcsecond resolution
• The radio structure of the $\gamma$-ray narrow-line Seyfert 1 galaxy SDSS J211852.96$-$073227.5
• Two active states of the narrow-line gamma-ray-loud AGN GB 1310+487
• Megaparsec-scale Radio Structure Associated with a Hybrid Blazar SBS B1646+499: Episodic Jet Activity with Precessing Axis
• The Connection between Radio and Gamma Ray Emission in Fermi/LAT Blazars
• Spatial variations of magnetic field along active galactic nuclei jets on sub-pc to Mpc scales
• Serendipitous Detection of HI Absorption Sets the True Redshift of 4C +15.05 to $z=0.833$
• The importance of jet bending in gamma-ray AGN - revisited
• Is BZB J1450+5201 the most distant $\gamma$-ray BL Lacertae object?
• Superluminal Motion and Jet Parameters in the Gamma-ray-Emitting Narrow-Line Seyfert 1 Galaxy TXS 1206+549
• The core dominance parameter and \emph{Fermi} detection of extragalactic radio sources
• Latest MAGIC discoveries pushing redshift boundaries in VHE Astrophysics
• Exploring the bulk of the BL Lac object population. II. Gamma-ray properties