X-ray emission from a rapidly accreting narrow-line Seyfert 1 galaxy at z=6.56

Abstract

This study aims at identifying luminous quasars at $z>5.7$ among X-ray-selected sources in the eROSITA Final Equatorial-Depth Survey (eFEDS) in order to place a lower limit on black hole accretion well into the epoch of re-ionisation. We confirm the low significance detection with eROSITA of a previously known, optically faint $z=6.56$ quasar from the Subaru High-z Exploration of Low-luminosity Quasars (SHELLQs) survey. We obtained a pointed follow-up observation of the source with the Chandra X-ray telescope in order to confirm the eROSITA detection. Using new near-infrared spectroscopy, we derived the physical properties of the super-massive black hole. Finally, we used this detection to infer a lower limit on the black hole accretion density rate at $z>6$. The Chandra observation confirms the eFEDS source as the most distant blind X-ray detection to date. The derived X-ray luminosity is high with respect to the rest-frame optical emission of the quasar. With a narrow MgII line, low derived black hole mass, and high Eddington ratio, as well as its steep photon index, the source shows properties that are similar to local narrow-line Seyfert 1 galaxies, which are thought to be powered by young super-massive black holes. In combination with a previous high-redshift quasar detection in the field, we show that quasars with $L_{2-10\mathrm{keV}}>10^{45}\mathrm{erg}{\mathrm{s}}^{-1}$ dominate accretion onto super-massive black holes at $z\sim 6$.

Accepted for publication in A&A

References in corpus (55)

• The UKIRT Infrared Deep Sky Survey (UKIDSS)
• HI4PI: A full-sky HI survey based on EBHIS and GASS
• UV Luminosity Functions at redshifts z~4 to z~10: 10000 Galaxies from HST Legacy Fields
• The eROSITA X-ray telescope on SRG
• An ultra-luminous quasar with a twelve-billion-solar-mass black hole at redshift 6.30
• Toward the Standard Population Synthesis Model of the X-Ray Background: Evolution of X-Ray Luminosity and Absorption Functions of Active Galactic Nuclei Including Compton-Thick Populations
• The Illustris simulation: the evolving population of black holes across cosmic time
• The X-ray-to-Optical Properties of Optically-Selected Active Galaxies Over Wide Luminosity and Redshift Ranges
• A Luminous Quasar at Redshift 7.642
• The X-ray Properties of the Most-Luminous Quasars from the Sloan Digital Sky Survey
• The Pan-STARRS1 distant z>5.6 quasar survey: more than 100 quasars within the first Gyr of the universe
• The SRG X-ray orbital observatory, its telescopes and first scientific results
• Third Data Release of the Hyper Suprime-Cam Subaru Strategic Program
• The eROSITA Final Equatorial Depth Survey (eFEDS): The X-ray catalog
• Universal bolometric corrections for AGN over 7 luminosity decades
• The Final SDSS High-Redshift Quasar Sample of 52 Quasars at z>5.7
• The CatWISE2020 Catalog
• Physical properties of 15 quasars at $z\gtrsim 6.5$
• Obscuration-dependent evolution of Active Galactic Nuclei
• X-CIGALE: fitting AGN/galaxy SEDs from X-ray to infrared
• The origins of massive black holes
• Four quasars above redshift 6 discovered by the Canada-France High-z Quasar Survey
• Fe II Emission in 14 Low-Redshift Quasars: I - Observations
• The Hard X-ray Spectral Slope as an Accretion-Rate Indicator in Radio-Quiet Active Galactic Nuclei
• High-redshift AGN in the Chandra Deep Fields: the obscured fraction and space density of the sub-$L_{\ast }$ population
• A new method for determining the sensitivity of X-ray imaging observations and the X-ray number counts
• The ASTRID simulation: the evolution of Supermassive Black Holes
• The eROSITA Final Equatorial-Depth Survey (eFEDS): Identification and characterization of the counterparts to the point-like sources
• Six more quasars at redshift 6 discovered by the Canada-France High-z Quasar Survey
• Detailed Shape and Evolutionary Behavior of the X-ray Luminosity Function of Active Galactic Nuclei
• A Chandra Search for Coronal X Rays from the Cool White Dwarf GD 356
• High redshift quasars in the COSMOS survey: the space density of z>3 X-ray selected QSOs
• Detecting and Characterizing Young Quasars I: Systemic Redshifts and Proximity Zones Measurements
• The Hard X-Ray Luminosity Function of High-Redshift ($3<z\lesssim 5$) Active Galactic Nuclei
• The eROSITA Final Equatorial-Depth Survey (eFEDS): The AGN Catalogue and its X-ray Spectral Properties
• The first blazar observed at z>6
• The discovery of a highly accreting, radio-loud quasar at z=6.82
• The WISSH quasars Project: II. Giant star nurseries in hyper-luminous quasars
• The deepest X-ray view of high-redshift galaxies: constraints on low-rate black-hole accretion
• Detecting and Characterizing Young Quasars II: Four Quasars at $z\sim 6$ with Lifetimes $<10^4$ years
• SRG/eROSITA uncovers the most X-ray luminous quasar at z>6
• Detecting clusters of galaxies and active galactic nuclei in an eROSITA all-sky survey digital twin
• The first measurement of the quasar lifetime distribution
• A Suzaku sample of unabsorbed narrow-line and broad-line Seyfert 1 galaxies: I. X-ray spectral properties
• First constraints on the AGN X-ray luminosity function at $z\sim 6$ from an eROSITA-detected quasar
• A comparison of hard X-ray photon indices and iron \ka emission lines in X-ray luminous narrow- and broad-line Seyfert 1 galaxies
• Establishing the X-ray Source Detection Strategy for eROSITA with Simulations
• X-ray properties of z>6.5 quasars
• Discovery of the most X-ray luminous quasar SRGE J170245.3+130104 at redshift z$\approx 5.5$
• XMM-Newton observations of the extremely X-ray luminous quasar CFHQS J142952+544717=SRGE J142952.1+544716 at redshift z=6.18
• Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs). XI. Proximity Zone Analysis for Faint Quasar Spectra at z~6
• A comparison of X-ray photon indices among the narrow and broad-line Seyfert 1 galaxies
• Deep XMM-Newton Observations of an X-ray Weak, Broad Absorption Line Quasar at $z=6.5$
• Discovery of a very Lyman-$\alpha$-luminous quasar at z=6.62
• High-redshift Narrow-line Seyfert 1 Galaxies: A Candidate Sample

Cited by in corpus (9)

• On the cosmic evolution of AGN obscuration and the X-ray luminosity function: XMM-Newton and Chandra spectral analysis of the 31.3 deg${}^2$ Stripe 82X
• HYPerluminous quasars at the Epoch of ReionizatION (HYPERION). A new regime for the X-ray nuclear properties of the first quasars
• AGN X-ray luminosity function and absorption function in the Early Universe ($3\le z\le 6$)
• CircleZ: Reliable Photometric redshifts for AGN computed using only photometry from Legacy Survey Imaging for DESI
• The SRG/eROSITA All-Sky Survey: X-ray beacons at late cosmic dawn
• Comprehensive view on a $z\sim 6.5$ radio-loud QSO: from the radio to the optical/NIR to the X-ray band
• Investigating the origin of radio emission in candidate super-Eddington accreting black holes
• Modeling Cosmological Evolution of Jetted Seyfert Galaxies for z<10
• Identification of high-redshift X-ray active galactic nuclei in the 4XMM-DR11 serendipitous catalogue using DES data: Comparative analysis with optically-selected QSOs