Very High Redshift X-ray Selected AGN in the Chandra Deep Field-North

Abstract

Deep Chandra X-ray exposures provide an efficient route for locating optically faint active galactic nuclei (AGN) at high redshifts. We use deep multicolor optical data to search for z>5 AGN in the 2 Ms X-ray exposure of the Chandra Deep Field-North. Of the 423 X-ray sources bright enough (z'<25.2) for a color-color analysis, at most one lies at z=5-6 and none at z>6. The z>5 object is spectroscopically confirmed at z=5.19. Only 31 of the 77 sources with z'>25.2 are undetected in the B or V bands at the 2-sigma level and could lie at z>5. There are too few moderate luminosity AGN at z=5-6.5 to ionize the intergalactic medium.

5 pages, accepted by The Astrophysical Journal Letters

References in corpus (1)

• The Redshift Evolution of the 2-8 keV X-ray Luminosity Function

Cited by in corpus (75)

• An Observational Determination of the Bolometric Quasar Luminosity Function
• The Chandra Deep Field-North Survey. XIII. 2 Ms Point-Source Catalogs
• The Chandra Deep Field South: Optical Spectroscopy I
• What Drives the Growth of Black Holes?
• Self-Consistent Models of the AGN and Black Hole Populations: Duty Cycles, Accretion Rates, and the Mean Radiative Efficiency
• Deep Extragalactic X-ray Surveys
• Cosmological simulations of black hole growth: AGN luminosities and downsizing
• Self-Regulated Growth of Supermassive Black Holes in Galaxies as the Origin of the Optical and X-ray Luminosity Functions of Quasars
• The Cosmic Evolution of Hard X-ray Selected Active Galactic Nuclei
• The observed ionization rate of the intergalactic medium and the ionizing emissivity at z >5: Evidence for a photon starved and extended epoch of reionization
• Super-massive Black Hole Demography: the Match between the Local and Accreted Mass Functions
• Cosmic X-ray Surveys of Distant Active Galaxies: The Demographics, Physics, and Ecology of Growing Supermassive Black Holes
• Quasar Feedback: the Missing Link in Structure Formation
• The Luminosity Function of X-ray Selected Active Galactic Nuclei: Evolution of Supermassive Black Holes at High Redshift
• The z=5 Quasar Luminosity Function from SDSS Stripe 82
• Probing reionization with Lyman-alpha emission lines
• Quasars at z=6: the survival of the fittest
• The Redshift Evolution of the 2-8 keV X-ray Luminosity Function
• The Changing AGN Population
• Black hole growth and activity in a LambdaCDM Universe
• An overdensity of galaxies at z=5.9 +/-0.2 in the Ultra Deep Field confirmed using the ACS grism
• Origin of the anti-hierarchical growth of black holes
• Modeling the cosmological co-evolution of supermassive black holes and galaxies: I. BH scaling relations and the AGN luminosity function
• The Abundance of Low-luminosity Lyman alpha Emitters at High Redshift
• Measuring the Sources of the Intergalactic Ionizing Flux
• The Luminosity Function of high-redshift QSOs - A combined analysis of GOODS and SDSS
• The X-ray luminosity function of Active Galactic Nuclei in the redshift interval z=3-5
• The accretion history of the Universe with the SKA
• The deepest X-ray view of high-redshift galaxies: constraints on low-rate black-hole accretion
• How are AGN Found?
• A Possible New Population of Sources with Extreme X-Ray / Optical Ratios
• The Faintest X-ray Sources from z=0-8
• Co-moving space density of X-ray-selected Active Galactic Nuclei
• X-ray Properties of Lyman Break Galaxies in the Great Observatories Origins Deep Survey
• Finding Rare AGN: XMM-Newton and Chandra Observations of SDSS Stripe 82
• The Discovery of Three New z>5 Quasars in the AGN and Galaxy Evolution Survey
• The Space Density of High-Redshift QSOs in the GOODS Survey
• First results from the Canada-France High-z Quasar Survey: Constraints on the z=6 quasar luminosity function and the quasar contribution to reionization
• The Chandra Deep Fields: Lifting the Veil on Distant Active Galactic Nuclei and X-Ray Emitting Galaxies
• Modeling the Counts of Faint Radio Loud Quasars: Constraints on the Supermassive Black Hole Population and Predictions for High Redshift
• High redshift quasars and the supermassive black hole mass budget: constraints on quasar formation models
• An XMM-Newton Study of the Hard X-ray Sky
• Constraining the Quasar Contribution to the Reionisation of Cosmic Hydrogen
• First constraints on the AGN X-ray luminosity function at $z\sim 6$ from an eROSITA-detected quasar
• Faint-end Quasar Luminosity Functions from Cosmological Hydrodynamic Simulations
• A V-Band Survey for Variable Galactic Nuclei in the Hubble Deep Field
• The clustering of X-ray selected AGN at z=0.1
• Discovery of an Optically-Faint Quasar at z=5.70 and Implications for the Faint End of the Quasar Luminosity Function
• The Space Density of Moderate Luminosity Active Galaxies at z=3
• Unresolved X-ray background: clues on galactic nuclear activity at z>6
• Variability and Multiwavelength Detected AGN in the GOODS Fields
• The Properties of Galaxies at z>5
• The DEEP Groth Strip Survey VI. Spectroscopic, Variability, and X-ray Detection of AGN
• Probing the existence of a rich galaxy overdensity at z=5.2
• Calibrating the Galaxy Halo - Black Hole Relation Based on the Clustering of Quasars
• Identifying high redshift AGNs using X-ray hardness
• 172 ks Chandra Exposure of the LALA Boötes Field: X-ray Source Catalog
• Early Black Holes in Cosmological Simulations: Luminosity Functions and Clustering Behaviour
• The Number Density of Intermediate and High Luminosity Active Galactic Nuclei at z~2-3
• Optical and infrared properties of active galactic nuclei in the Lockman Hole
• The Wide Field Imager Lyman-Alpha Search (WFILAS) for Galaxies at Redshift ~5.7: II. Survey Design and Sample Analysis
• The Formation and Evolution of the First Massive Black Holes
• A simple model for the evolution of super-massive black holes and the quasar population
• Star Formation and X-ray Emission in Distant Star Forming Galaxies
• The Infrared Medium-deep Survey. \Romannum{7}. Faint Quasars at $z\sim 5$ in the ELAIS-N1 Field
• Lyman Alpha Constraints on Very Low Luminosity AGN
• On the Absence of High-Redshift AGNs: Little Growth in the Supermassive Black Hole Population at High Redshifts
• Evolution of the anti-truncated stellar profiles of S0 galaxies since $z=0.6$ in the SHARDS survey: I - Sample and Methods
• Optically faint X-ray sources in the CDFN: Spitzer constraints
• Surveys of the Cosmic X-ray Background
• z ~ 2.5 - 3 Ionizers in the GOODS-N Field
• X-rays from the First Massive Black Holes
• Near-Infrared Properties of Faint X-rays Sources from NICMOS Imaging in the Chandra Deep Fields
• Candidate z ~ 2.5 Lyman Continuum Sources in the GOODS Fields
• X-ray Survey Results on Active Galaxy Physics and Evolution