VLBI Observations of a sample of Palomar-Green quasars I: parsec-scale morphology

Abstract

We observed 20 Palomar-Green (PG) quasars at low redshift ($z<0.5$) with total flux density > 1 mJy, including 4 radio-loud quasars (RLQs) and 16 radio-quiet quasars (RQQs), using the Very Long Baseline Array (VLBA) at 5 GHz. Ten RQQs are clearly detected in the VLBA images, and a compact radio core is identified in eight of them, indicating the prevalence of active galactic nucleus (AGN)-related radio emission in this flux-density-limited RQQ sample. The RQQs and RLQs in our sample have a division at $\sim$30~mJy. The radio emission from RQQs appears to be the result of a combination of star formation and AGN-associated activities. All RQQs in our sample have a 5 GHz flux density ratio of Very Large Array (VLA) A-array to D-array $f_{\mathrm{c}}=S_{\mathrm{A}}^{\mathrm{VLA}}/S_{\mathrm{D}}^{\mathrm{VLA}}$ above 0.2. The RQQs with $f_a$ (VLBA and VLA flux density ratio $S^{\mathrm{VLBA}}/S_{\mathrm{A}}^{\mathrm{VLA}})>0.2$ versus $f_a<0.2$ show significant differences in morphology, compactness and total flux density. $f_{\mathrm{a}}$ of RQQs is systematically lower than that of RLQs, probably due to the extended jets or relic jets of RQQs on 10s to 100s parsecs which are resolved out in VLBA images. Future larger samples, especially with the addition of milli-arcsec resolution radio images of RQQs with total flux densities below 1 mJy, can test the conclusions of this paper and contributes to the understanding of the radio emission mechanism of RQQs, and the dichotomy and physical connection between RQQs and RLQs.

arXiv commentThis paper has been accepted by MNRAS

References in corpus (79)

• The Eleventh and Twelfth Data Releases of the Sloan Digital Sky Survey: Final Data from SDSS-III
• Reverberation Measurements for 17 Quasars and the Size-Mass-Luminosity Relations in Active Galactic Nuclei
• Central Masses and Broad-Line Region Sizes of Active Galactic Nuclei. II. A Homogeneous Analysis of a Large Reverberation-Mapping Database
• Determining Central Black Hole Masses in Distant Active Galaxies and Quasars. II. Improved Optical and UV Scaling Relationships
• Radio Properties of Infrared Selected Galaxies in the IRAS 2 Jy Sample
• Relativistic Jets in Active Galactic Nuclei
• GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) survey I: A low-frequency extragalactic catalogue
• DiFX2: A more flexible, efficient, robust and powerful software correlator
• A high velocity ionised outflow and XUV photosphere in the narrow emission line quasar PG1211+143
• Radio galaxies and feedback from AGN jets
• Optical Continuum and Emission-Line Variability of Seyfert 1 Galaxies
• CAIXA: a catalogue of AGN in the XMM-Newton archive III. Excess Variance Analysis
• Supermassive black holes with high accretion rates in active galactic nuclei: I. First results from a new reverberation mapping campaign
• The New Generation Atlas of Quasar Spectral Energy Distributions from Radio to X-rays
• Nuclear Luminosities and Radio Loudness of Seyfert Nuclei
• Gaia Early Data Release 3: Summary of the contents and survey properties
• The Dynamic Evolution of Young Extragalactic Radio Sources
• Dating COINS: Kinematic Ages for Compact Symmetric Objects
• VLBI Images of 49 Radio Supernovae in Arp 220
• Radio Loud and Radio Quiet Quasars
• The VLA Survey of the Chandra Deep Field South. V. Evolution and Luminosity Functions of sub-mJy radio sources and the issue of radio emission in radio-quiet AGN
• VLBA Imaging of Central Engines in Radio Quiet Quasars
• The radio properties of radio-quiet quasars
• The radio properties of radio-quiet quasars
• AGN and Starburst Radio Emission from Optically Selected QSOs
• Radio Variability of Radio Quiet and Radio Loud Quasars
• The radio structure of radio-quiet quasars
• Radio faint AGN: a tale of two populations
• The faintest Seyfert radio cores revealed by VLBI
• The radio spectra of the compact sources in Arp 220: A mixed population of supernovae and supernova remnants
• Motion and Properties of Nuclear Radio Components in Seyfert Galaxies Seen with VLBI
• Super-Eddington accreting massive black holes as long-lived cosmological standards
• The COINS Sample - VLBA Identifications of Compact Symmetric Objects
• LeMMINGs. I. The eMERLIN legacy survey of nearby galaxies. 1.5-GHz parsec-scale radio structures and cores
• On the Gas Content and Efficiency of AGN Feedback in Low-redshift Quasars
• The central engines of radio-quiet quasars
• Dense Molecular Gas and the Role of Star Formation in the Host Galaxies of Quasi-Stellar Objects
• Quasars That Have Transitioned from Radio-quiet to Radio-loud on Decadal Timescales Revealed by VLASS and FIRST
• XMM-Newton observations of the Narrow-Line Seyfert 1 galaxy Mrk 335 in an historical low X-ray flux state
• VLBI observations of 10 CSO candidates: expansion velocities of hot spots
• Radio-Quiet Quasars in the VIDEO Survey: Evidence for AGN-powered radio emission at S_1.4GHz < 1 mJy
• Confirming the high velocity outflow in PG 1211+143
• Sub-parsec radio cores in nearby Seyfert galaxies
• Magellan Spectroscopy of Low-Redshift Active Galactic Nuclei
• A remarkable long-term light curve, and deep, low-state spectroscopy: Swift & XMM-Newton monitoring of the NLS1 galaxy Mkn 335
• What drives the radio slopes in radio quiet quasars?
• Very Long Baseline Array Imaging of Parsec-scale Radio Emissions in Nearby Radio-quiet Narrow-line Seyfert 1 Galaxies
• Eleven years of monitoring the Seyfert 1 Mrk 335 with Swift: Characterizing the X-ray and UV/optical variability
• The radio loudness of SDSS quasars from the LOFAR Two-metre Sky Survey: ubiquitous jet activity and constraints on star formation
• Stellar Photometric Structures of the Host Galaxies of Nearby Type 1 Active Galactic Nuclei
• Stellar Populations in the Host Galaxies of Mrk 1014, IRAS 07598+6508, and Mrk 231
• Infrared spectra and photometry of complete samples of PG and 2MASS quasars
• Unveiling the origin of the radio emission in radio-quiet quasars
• An ALMA CO(2-1) Survey of Nearby Palomar-Green Quasars
• Galactic Rings Revisited. I. CVRHS Classifications of 3962 Ringed Galaxies from the Galaxy Zoo 2 Database
• Kinematics of the parsec-scale radio jet in 3C48
• Herschel Survey of the Palomar-Green QSOs at Low Redshift
• The Infrared Emission and Vigorous Star Formation of Low-redshift Quasars
• Jet-cloud collisions in the jet of the Seyfert galaxy NGC3079
• LeMMINGs. II. The e-MERLIN legacy survey of nearby galaxies. The deepest radio view of the Palomar sample on parsec scale
• The Diverse Morphology, Stellar Population, and Black Hole Scaling Relations of the Host Galaxies of Nearby Quasars
• Status and progress of China SKA Regional Centre prototype
• Detection of a Parsec-Scale Jet in a Radio-Quiet Narrow-Line Seyfert 1 Galaxy with Highly Accreting Supermassive Black Hole
• Lifting the curtain: The Seyfert galaxy Mrk 335 emerges from deep low-state in a sequence of rapid flare events
• Outflows in the Radio-Intermediate Quasar III Zw 2: A Polarization Study with the EVLA & uGMRT
• The GLEAM 4-Jy (G4Jy) Sample: II. Host-galaxy identification for individual sources
• The obstructed jet in Mrk 231
• The GLEAM 4-Jy (G4Jy) Sample: I. Definition and the catalogue
• Discovery of hard X-ray delays in the X-ray emission of the Seyfert 1 galaxy Mrk~110: possible evidence for Comptonization
• The radio structure of 3C 316, a galaxy with double-peaked narrow optical emission lines
• Tracking the year-to-year variation in the spectral energy distribution of the Narrow-line Seyfert 1 Galaxy Mrk335
• Dependence of the Radio Emission on the Eddington Ratio of Radio-Quiet Quasars
• Daily variability at milli-arcsecond scales in the radio quiet NLSy1 Mrk 110
• Detection of a variable ultra-fast outflow in the Narrow Line Seyfert 1 galaxy PG 1448+273
• The radio core and jet in the broad absorption line quasar PG 1700+518
• The nearby extreme accretion and feedback system PDS 456: finding a complex radio-emitting nucleus
• The Emission Structure of Formaldehyde MegaMasers
• A Blazar-Like Radio Flare in Mrk 231
• High-redshift obscured quasars: radio emission at sub-kiloparsec scales

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