High-resolution double morphology of the most distant known radio quasar at z=6.12

Abstract

Context: The highest redshift quasars at z>~6 receive considerable attention since they provide strong constraints on the growth of the earliest supermassive black holes. They also probe the epoch of reionisation and serve as "lighthouses" to illuminate the space between them and the observer. The source J1427+3312 (z=6.12) has recently been identified as the first and so far the only known radio-loud quasar at z>6. Aims: We investigated the compact radio structure of J1427+3312 on milli-arcsecond (mas) angular scales, to compare it with that of the second most distant radio-loud quasar J0836+0054 (z=5.77) and with lower-redshift radio quasars in general. Methods: We observed J1427+3312 in phase-reference mode with ten antennas of the European Very Long Baseline Interferometry (VLBI) Network (EVN) at 1.6 GHz on 11 March 2007 and at 5 GHz on 3 March 2007. Results: The source was clearly detected at both frequencies. At 1.6 GHz, it shows a prominent double structure. The two components are separated by 8.3 mas, corresponding to a projected linear distance of ~160 pc. Both components with sub-mJy flux densities appear resolved. In the position of the brightest component at 1.6 GHz, we detected mas-scale radio emission at 5 GHz as well. The radio spectrum of this feature is steep. The double structure and the separation of the components of J1427+3312 are similar to those of the young (<~10^4 yr) compact symmetric objects (CSOs).

arXiv comment4 pages, 2 figures, accepted for Astronomy & Astrophysics as a Letter to the Editor

References in corpus (17)

• Simulating the joint evolution of quasars, galaxies and their large-scale distribution
• Properties of Radio-Selected Broad Absorption-Line Quasars from the FIRST Survey
• Field Galaxy Evolution Since Z~1 from a Sample of QSO Absorption-Selected Galaxies
• A Survey of z~6 Quasars in the SDSS Deep Stripe: I. a Flux-Limited Sample at z_{AB}<21
• XBootes: An X-Ray Survey of the NDWFS Bootes Field - Paper I Overview and Initial Results
• The inevitable youthfulness of known high-redshift radio galaxies
• Lensing, reddening and extinction effects of MgII absorbers from z=0.4 to z=2
• Deep Westerbork 1.4 GHz Imaging of the Bootes Field
• A Deep VLA survey at 20cm of the ISO ELAIS survey regions
• Kinematic Age Estimates for 4 Compact Symmetric Objects from the Pearson-Readhead Survey
• Discovery of a z=6.1 Radio-Loud Quasar in the NDWFS
• Gravitational lenses magnify up to one third of the most distant quasars
• On the redshift cut-off for flat-spectrum radio sources
• Mid-Infrared Selection of Brown Dwarfs and High-Redshift Quasars
• Modeling the Counts of Faint Radio Loud Quasars: Constraints on the Supermassive Black Hole Population and Predictions for High Redshift
• High-resolution radio imaging of the most distant radio quasar SDSS J0836+0054
• Radio structure of the most distant radio-detected quasar at the ten milli- arcsecond scale

Cited by in corpus (30)

• Science with a lunar low-frequency array: from the dark ages of the Universe to nearby exoplanets
• Constraining the radio-loud fraction of quasars at z>5.5
• The first blazar observed at z>6
• The discovery of a highly accreting, radio-loud quasar at z=6.82
• 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
• The space density of z>4 blazars
• Resolving the Powerful Radio-loud Quasar at z~6
• VLBI observations of the radio quasar J2228+0110 at z=5.95 and other field sources in multiple-phase-centre mode
• High-redshift quasars at $z\ge 3$ -- I. Radio spectra
• J0906+6930: a radio-loud quasar in the early Universe
• High-resolution images of five radio quasars at early cosmological epochs
• A new version of the OCARS catalog of Optical Characteristics of Astrometric Radio Sources
• Resolving the Radio Emission from the Quasar P172+18 at $z=6.82$
• The radio spectral turnover of radio-loud quasars at $z>5$
• Radio-loud Quasars above Redshift 4: VLBI Imaging of an Extended Sample
• Multi-frequency polarization properties of ten quasars on deca-parsec scales at z > 3
• VLBI observation of the newly discovered z=5.18 quasar SDSS J0131-0321
• Radio Jet Proper-motion Analysis of Nine Distant Quasars above Redshift 3.5
• VLBI observations of VIK J2318-3113, a quasar at z = 6.44
• Milli-arcsecond imaging of the radio emission from the quasar with the most massive black hole at reionization
• A compact symmetric radio source born at one-tenth the current age of the Universe
• Constraining the Radio Properties of the $z$=6.44 QSO VIK J2318$-$3113
• Observations by GMRT at 323 MHz of radio-loud quasars at $z>5$
• VLBI search for the radio counterpart of HESS J1943+213
• J2102+6015: a young radio source at z = 4.575
• Revealing faint compact radio jets at redshifts above 5 with very long baseline interferometry
• Multi-scale Radio and X-ray Structure of the High-redshift Quasar PMN J0909+0354
• High-resolution Imaging of Two Radio Quasars at the End of the Reionization Epoch
• Milliarcsecond-scale radio structure of the most distant BL Lac object candidate at redshift 6.57