Comprehensive view on a $z\sim 6.5$ radio-loud QSO: from the radio to the optical/NIR to the X-ray band

Abstract

We present a multi-wavelength analysis, from the radio to the X-ray band, of the redshift $z=6.44$ VIK J2318$-$31 radio-loud (RL) quasi stellar object (QSO), one of the most distant currently known in this class. The work is based on newly obtained (uGMRT, ATCA, Chandra) as well as archival (GNIRS and X-Shooter) dedicated observations that have not been published yet. Based on the observed X-ray and radio emission, its relativistic jets are likely young and misaligned from our line of sight. Moreover, we can confirm, with simultaneous observations, the presence of a turnover in the radio spectrum at ${\nu }_{\mathrm{peak}}\sim 650$ MHz which is unlikely to be associated with self-synchrotron absorption. From the NIR spectrum we derived the mass of the central black hole, M${}_{\mathrm{BH}}=8.1_{-5.6}^{+6.8}\times 10^8{\mathrm{M}}_{\odot }$, and the Eddington ratio, ${\lambda }_{\mathrm{EDD}}=0.8_{-0.6}^{+0.8}$, using broad emission lines as well as an accretion disc model fit to the continuum emission. Given the high accretion rate, the presence of a $\sim$8$\times$10${}^8$ M${}_{\odot }$ black hole at $z=6.44$ can be explained by a seed black hole ($\sim$10${}^4$ M${}_{\odot }$) that formed at $z\sim 25$, assuming a radiative efficiency ${\eta }_{\mathrm{d}}\sim 0.1$. However, by assuming ${\eta }_{\mathrm{d}}\sim 0.3$, as expected for jetted systems, the mass observed would challenge current theoretical models of black hole formation.

Accepted for publication on A&A the 22nd April 2024

References in corpus (58)

• HI4PI: A full-sky HI survey based on EBHIS and GASS
• The LOFAR Two-metre Sky Survey - I. Survey Description and Preliminary Data Release
• GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) survey I: A low-frequency extragalactic catalogue
• Biases in Virial Black Hole Masses: An SDSS Perspective
• The LOFAR Two-metre Sky Survey -- V. Second data release
• The Pan-STARRS1 distant z>5.6 quasar survey: more than 100 quasars within the first Gyr of the universe
• The Bolometric Quasar Luminosity Function at z = 0-7
• Physical properties of 15 quasars at $z\gtrsim 6.5$
• Formation of the first nuclear clusters and massive black holes at high redshift
• The Rapid ASKAP Continuum Survey I: Design and First Results
• The origins of massive black holes
• Compact steep-spectrum and peaked-spectrum radio sources
• The Dynamic Evolution of Young Extragalactic Radio Sources
• Correcting CIV-Based Virial Black Hole Masses
• Extragalactic Peaked-Spectrum Radio Sources at Low Frequencies
• Initial mass function of intermediate mass black hole seeds
• Kiloparsec-scale ALMA Imaging of [CII] and Dust Continuum Emission of 27 Quasar Host Galaxies at z~6
• Correcting for Telluric Absorption: Methods, Case Studies, and Release of the TelFit Code
• The Kinematics of z ~ 6 Quasar Host Galaxies
• On the two main classes of Active Galactic Nuclei
• The X-shooter/ALMA Sample of Quasars in the Epoch of Reionization. II. Black Hole Masses, Eddington Ratios, and the Formation of the First Quasars
• The first blazar observed at z>6
• The discovery of a highly accreting, radio-loud quasar at z=6.82
• Conditions for Optimal Growth of Black Hole Seeds
• CAPTURE: A continuum imaging pipeline for the uGMRT
• Mega parsec relativistic jets launched from an accreting supermassive blackhole in an extreme spiral galaxy
• Quasars as standard candles II: The non linear relation between UV and X-ray emission at high redshifts
• The Rapid ASKAP Continuum Survey IV: continuum imaging at 1367.5 MHz and the first data release of RACS-mid
• ALMA Confirmation of an Obscured Hyperluminous Radio-Loud AGN at $z=6.853$ Associated with a Dusty Starburst in the 1.5 deg${}^2$ COSMOS Field
• SRG/eROSITA uncovers the most X-ray luminous quasar at z>6
• XQR-30: Black Hole Masses and Accretion Rates of 42 z>6 Quasars
• The Pan-STARRS1 z>5.6 quasar survey II: Discovery of 55 Quasars at 5.6<z<6.5
• Evolving parsec-scale radio structure in the most distant blazar known
• Parsec-scale properties of the radio brightest jetted AGN at z > 6
• Jet enhanced accretion growth of supermassive black holes
• Discovery of 24 radio-bright quasars at $4.9\le z\le 6.6$ using low-frequency radio observations
• Radio Detection of VIK J2318$-$3113, the Most Distant Radio-Loud Quasar ($z$=6.44)
• SDSS J013127.34-032100.1: a candidate blazar with a 11 billion solar mass black hole at $z$=5.18
• Radio and Far-IR Emission Associated with a Massive Star-forming Galaxy Candidate at z$\simeq$6.8: A Radio-Loud AGN in the Reionization Era?
• SDSS J013127.34$-$032100.1: A newly discovered radio-loud quasar at $z=5.18$ with extremely high luminosity
• Remnant Radio Galaxies Discovered in a Multi-frequency Survey
• Direct observation of an extended X-ray jet at $z$=6.1
• The evolution of the heaviest super-massive black-holes in jetted AGNs
• The radio spectral turnover of radio-loud quasars at $z>5$
• New Radio-Loud QSOs at the end of the Re-ionisation Epoch
• Blazar nature of high-z radio-loud quasars
• The Blueshift Of Civ Broad Emission Line In Qsos
• The First Gamma-ray Emitting BL Lacertae Object at the Cosmic Dawn
• SAGAN -- III: New insights into giant radio quasars
• Radio spectrum evolution and magnetic field in extreme GPS radio sources. The case of RXJ1459+3337
• X-ray emission from a rapidly accreting narrow-line Seyfert 1 galaxy at z=6.56
• VLBI observations of VIK J2318-3113, a quasar at z = 6.44
• The central engine of the highest redshift blazar
• The GLEAMing of the First Supermassive Black Holes
• Observations by GMRT at 323 MHz of radio-loud quasars at $z>5$
• Constraining the Radio Properties of the $z$=6.44 QSO VIK J2318$-$3113
• A powerful (and likely young) radio-loud quasar at z=5.3
• Milliarcsecond Structures of Variable Peaked-Spectrum Sources

Cited by in corpus (4)

• The SRG/eROSITA All-Sky Survey: X-ray beacons at late cosmic dawn
• The host galaxies of radio-loud quasars at z>5 with ALMA
• Multi-wavelength properties of three new radio-powerful $z\sim 5.6$ quasi-stellar objects discovered from RACS
• High-$z$ radio Quasars in RACS I: Selection, identification, and multi-wavelength properties