Revealing faint compact radio jets at redshifts above 5 with very long baseline interferometry

Abstract

Over the past two decades, our knowledge of the high-redshift (z > 5) radio quasars has expanded, thanks to dedicated high-resolution very long baseline interferometry (VLBI) observations. Distant quasars provide unique information about the formation and evolution of the first galaxies and supermassive black holes in the Universe. Powerful relativistic jets are likely to have played an essential role in these processes. However, the sample of VLBI-observed radio quasars is still too small to allow meaningful statistical conclusions. We extend the list of the VLBI observed radio quasars to investigate how the source structure and physical parameters are related to radio loudness. We assembled a sample of 10 faint radio quasars located at 5 < z < 6 with their radio-loudness indices spanning between 0.9-76. We observed the selected targets with the European VLBI Network (EVN) at 1.7 GHz. The milliarcsecond-scale resolution of VLBI at this frequency allows us to probe the compact innermost parts of radio-emitting relativistic jets. In addition to the single-band VLBI observations, we collected single-dish and low-resolution radio interferometric data to investigate the spectral properties and variability of our sources. The detection rate of this high-redshift, low-flux-density sample is 90%, with only one target (J0306+1853) remaining undetected. The other 9 sources appear core-dominated and show a single, faint and compact radio core on this angular scale. The derived radio powers are typical of FRII radio galaxies and quasars. By extending our sample with other VLBI-detected z > 5 sources from the literature, we found that the core brightness temperatures and monochromatic radio powers tend to increase with radio loudness.

References in corpus (96)

• The Gaia mission
• Gaia Data Release 3: Summary of the content and survey properties
• A Cosmology Calculator for the World Wide Web
• Relativistic Jets in Active Galactic Nuclei
• An ultra-luminous quasar with a twelve-billion-solar-mass black hole at redshift 6.30
• The Assembly of the First Massive Black Holes
• Optical and Radio Properties of Extragalactic Sources Observed by the FIRST and SDSS Surveys
• Star Formation and Gas Kinematics of Quasar Host Galaxies at z~6: New insights from ALMA
• The Pan-STARRS1 distant z>5.6 quasar survey: more than 100 quasars within the first Gyr of the universe
• Sub-milliarcsecond Imaging of Quasars and Active Galactic Nuclei. IV. Fine Scale Structure
• The Early Data Release of the Dark Energy Spectroscopic Instrument
• The Final SDSS High-Redshift Quasar Sample of 52 Quasars at z>5.7
• The Formation and Evolution of Massive Black Holes
• The third realization of the International Celestial Reference Frame by very long baseline interferometry
• VLBI Observations of a Complete Sample of Radio Galaxies. 10 Years Later
• Compact steep-spectrum and peaked-spectrum radio sources
• Evidence for non-evolving FeII/MgII ratios in rapidly accreting z~6 QSOs
• A Quick Look at the $3$GHz Radio Sky I. Source Statistics from the Very Large Array Sky Survey
• The Dynamic Evolution of Young Extragalactic Radio Sources
• Gemini GNIRS near-infrared spectroscopy of 50 quasars at z>~5.7
• A VLBA survey of the core shift effect in AGN jets I. Evidence for dominating synchrotron opacity
• Exploring Reionization-Era Quasars III: Discovery of 16 Quasars at $6.4\lesssim z\lesssim 6.9$ with DESI Legacy Imaging Surveys and UKIRT Hemisphere Survey and Quasar Luminosity Function at $z\sim 6.7$
• A Global 86GHz VLBI Survey of Compact Radio Sources
• High-Redshift Quasars Found in Sloan Digital Sky Survey Commissioning Data
• Radio Loud and Radio Quiet Quasars
• The SFXC software correlator for Very Long Baseline Interferometry: Algorithms and Implementation
• VLBA Imaging of Central Engines in Radio Quiet Quasars
• Radio faint AGN: a tale of two populations
• The faintest Seyfert radio cores revealed by VLBI
• Constraining the radio-loud fraction of quasars at z>5.5
• Motion and Properties of Nuclear Radio Components in Seyfert Galaxies Seen with VLBI
• LeMMINGs. I. The eMERLIN legacy survey of nearby galaxies. 1.5-GHz parsec-scale radio structures and cores
• A survey of luminous high-redshift quasars with SDSS and WISE. I. target selection and optical spectroscopy
• The central engines of radio-quiet quasars
• VLBI-Gaia offsets favor parsec-scale jet direction in Active Galactic Nuclei
• High-resolution VLA Imaging of SDSS Stripe 82 at 1.4 GHz
• The first blazar observed at z>6
• The discovery of a highly accreting, radio-loud quasar at z=6.82
• A survey of luminous high-redshift quasars with SDSS and WISE II. the bright end of the quasar luminosity function at z ~ 5
• VLBI observations of 10 CSO candidates: expansion velocities of hot spots
• A quantitative analysis of systematic differences in positions and proper motions of Gaia DR2 with respect to VLBI
• Radio astrometry with chromatic AGN core positions
• Sub-parsec radio cores in nearby Seyfert galaxies
• Compact Symmetric Objects and Supermassive Binary Black Holes in the VLBA Imaging and Polarimetry Survey
• Dissecting the AGN disk-jet system with joint VLBI-Gaia analysis
• The role of relativistic jets in the heaviest and most active supermassive black holes at high redshift
• Blazar candidates beyond redshift 4 observed by Swift
• Wide-field VLBA Observations of the Chandra Deep Field South
• The first estimate of radio jet proper motion at z>5
• On the nature of bright compact radio sources at z>4.5
• Into the central 10 pc of the most distant known radio quasar. VLBI imaging observations of J1429+5447 at z=6.21
• Unveiling the origin of the radio emission in radio-quiet quasars
• Constraining the quasar radio-loud fraction at $z\sim 6$ with deep radio observations
• Parsec-scale properties of the radio brightest jetted AGN at z > 6
• SDSS J102623.61+254259.5: the second most distant blazar at z=5.3
• High-resolution double morphology of the most distant known radio quasar at z=6.12
• LeMMINGs. II. The e-MERLIN legacy survey of nearby galaxies. The deepest radio view of the Palomar sample on parsec scale
• An ultra-luminous quasar at z=5.363 with a ten billion solar mass black hole and a Metal-Rich DLA at z~5
• Radio Detection of VIK J2318$-$3113, the Most Distant Radio-Loud Quasar ($z$=6.44)
• Resolving the Powerful Radio-loud Quasar at z~6
• A deep / wide 1-2 GHz snapshot survey of SDSS Stripe 82 using the Karl G. Jansky Very Large Array in a compact hybrid configuration
• VLA and VLBA Observations of the Highest Redshift Radio-Loud QSO J1427+3312 at z = 6.12
• Radio structure of the most distant radio-detected quasar at the ten milli- arcsecond scale
• Radio-Selected Quasars in the Sloan Digital Sky Survey
• The Near and Mid-infrared photometric properties of known redshift $z\ge 5$ Quasars
• SDSS J013127.34-032100.1: a candidate blazar with a 11 billion solar mass black hole at $z$=5.18
• High-redshift quasars at $z\ge 3$ -- I. Radio spectra
• VLBI observations of the radio quasar J2228+0110 at z=5.95 and other field sources in multiple-phase-centre mode
• On the coherence loss in phase-referenced VLBI observations
• High-resolution images of five radio quasars at early cosmological epochs
• VLBI Observations of a sample of Palomar-Green quasars I: parsec-scale morphology
• Resolving the Radio Emission from the Quasar P172+18 at $z=6.82$
• A Survey for High-redshift Gravitationally Lensed Quasars and Close Quasars Pairs. I. the Discoveries of an Intermediately-lensed Quasar and a Kpc-scale Quasar Pair at $z\sim 5$
• Dark bubbles around high-redshift radio-loud AGN
• The radio spectral turnover of radio-loud quasars at $z>5$
• Radio-loud Quasars above Redshift 4: VLBI Imaging of an Extended Sample
• Blazar nature of high-z radio-loud quasars
• Observational Properties of Jets in Active Galactic Nuclei
• The FAST Core Array
• An extremely X--ray weak blazar at z=5
• VLBI observation of the newly discovered z=5.18 quasar SDSS J0131-0321
• VLBI observations of VIK J2318-3113, a quasar at z = 6.44
• Big and young supermassive black holes in the early Universe
• A compact symmetric radio source born at one-tenth the current age of the Universe
• Observations by GMRT at 323 MHz of radio-loud quasars at $z>5$
• Deep Extragalactic VLBI-Optical Survey (DEVOS): I. Pilot MERLIN and VLBI observations
• High-redshift obscured quasars: radio emission at sub-kiloparsec scales
• A powerful (and likely young) radio-loud quasar at z=5.3
• Radio-loud fraction of z>6 quasars
• Very long baseline interferometry observation of the triple AGN candidate J0849+1114
• High-redshift quasars at $z\ge 3$: radio variability and MPS/GPS candidates
• Is the X-ray bright z = 5.5 quasar SRGE J170245.3+130104 a blazar?
• Very long baseline interferometry observations of the high-redshift blazar candidate J0141-5427
• Exploring the radio spectral energy distribution of the ultraluminous radio-quiet quasar SDSS J0100+2802 at redshift 6.3
• High-Resolution Radio Observations of Five Optically Selected Type 2 Quasars
• VLBI observations of the high-redshift X-ray bright blazar SRGE J170245.3+130104

Cited by in corpus (4)

• The host galaxies of radio-loud quasars at z>5 with ALMA
• Radio-loudness statistics of quasars from Quaia-VLASS
• What is Inside the Double-Double Structure of the Radio Galaxy J0028+0035?
• Milliarcsecond-resolution Radio-imaging Survey of Blazar Candidates at 4 < z < 5.4