Redshift identification of X-ray selected active galactic nuclei in the J1030 field: searching for large-scale structures and high-redshift sources

Abstract

We publicly release the spectroscopic and photometric redshift catalog of the sources detected with Chandra in the field of the $z$=6.3 quasar SDSS J1030+0525. This is currently the fifth deepest X-ray field, and reaches a 0.5-2 keV flux limit $f_{0.5-2}$=6$\times$10${}^{-17}$ erg s${}^{-1}$ cm${}^{-2}$. By using two independent methods, we measure a photometric redshift for 243 objects, while 123 (51%) sources also have a spectroscopic redshift, 110 of which coming from an INAF-Large Binocular Telescope (LBT) Strategic Program. We use the spectroscopic redshifts to determine the quality of the photometric ones, and find it in agreement with that of other X-ray surveys which used a similar number of photometric data-points. In particular, we measure a sample normalized median absolute deviation ${\sigma }_{NMAD}$=1.48||$z_{phot}$-$z_{spec}$||/(1+$z_{spec}$)=0.065. We use these new spectroscopic and photometric redshifts to study the properties of the Chandra J1030 field. We observe several peaks in our spectroscopic redshift distribution between $z$=0.15 and $z$=1.5, and find that the sources in each peak are often distributed across the whole Chandra field of view. This evidence confirms that X-ray selected AGN can efficiently track large-scale structures over physical scales of several Mpc. Finally, we computed the Chandra J1030 $z>$3 number counts: while the spectroscopic completeness at high-redshift of our sample is limited, our results point towards a potential source excess at $z\ge$4, which we plan to either confirm or reject in the near future with dedicated spectroscopic campaigns.

arXiv comment21 pages, 15 figures. Accepted for publication in Astronomy and Astrophysics

References in corpus (52)

• Stellar population synthesis at the resolution of 2003
• The Dust Content and Opacity of Actively Star-Forming Galaxies
• EAZY: A Fast, Public Photometric Redshift Code
• The Sixteenth Data Release of the Sloan Digital Sky Surveys: First Release from the APOGEE-2 Southern Survey and Full Release of eBOSS Spectra
• COSMOS Photometric Redshifts with 30-bands for 2-deg2
• The COSMOS2015 Catalog: Exploring the 1<z<6 Universe with half a million galaxies
• Mass assembly in quiescent and star-forming galaxies since z=4 from UltraVISTA
• zCOSMOS: A Large VLT/VIMOS redshift survey covering 0 < z < 3 in the COSMOS field
• 3D-HST WFC3-selected Photometric Catalogs in the Five CANDELS/3D-HST Fields: Photometry, Photometric Redshifts and Stellar Masses
• A Survey of z>5.8 Quasars in the Sloan Digital Sky Survey I: Discovery of Three New Quasars and the Spatial Density of Luminous Quasars at z~6
• The synthesis of the cosmic X-ray background in the Chandra and XMM-Newton era
• Spectral Energy Distributions of Hard X-ray selected AGNs in the XMDS Survey
• Identifying Luminous AGN in Deep Surveys: Revised IRAC Selection Criteria
• AGN wind scaling relations and the co-evolution of black holes and galaxies
• The Chandra Deep Field-South Survey: 7 Ms Source Catalogs
• The Chandra COSMOS Legacy survey: overview and point source catalog
• Photometric redshift and classification for the XMM-COSMOS sources
• The Great Observatories Origins Deep Survey - VLT/VIMOS Spectroscopy in the GOODS-South Field: Part II
• Dissecting Photometric redshift for Active Galactic Nuclei using XMM- and Chandra-COSMOS samples
• The Multiwavelength Survey by Yale-Chile (MUSYC): Survey Design and Deep Public UBVRIz' Images and Catalogs of the Extended Hubble Deep Field South
• The Great Observatories Origins Deep Survey. VLT/VIMOS Spectroscopy in the GOODS-South Field
• The FourStar Galaxy Evolution Survey (ZFOURGE): ultraviolet to far-infrared catalogs, medium-bandwidth photometric redshifts with improved accuracy, stellar masses, and confirmation of quiescent galaxies to z~3.5
• Black hole masses and enrichment of z ~ 6 SDSS quasars
• The 4 Ms Chandra Deep Field-South Number Counts Apportioned by Source Class: Pervasive Active Galactic Nuclei and the Ascent of Normal Galaxies
• Evidence for non-evolving FeII/MgII ratios in rapidly accreting z~6 QSOs
• Spitzer's Contribution to the AGN Population
• High-redshift AGN in the Chandra Deep Fields: the obscured fraction and space density of the sub-$L_{\ast }$ population
• The 2 Ms Chandra Deep Field-North Survey and the 250 ks Extended Chandra Deep Field-South Survey: Improved Point-Source Catalogs
• Tracing the large scale structure in the Chandra Deep Field South
• AEGIS-X: Deep Chandra imaging of the Central Groth Strip
• CANDELS/GOODS-S, CDFS, ECDFS: Photometric Redshifts For Normal and for X-Ray-Detected Galaxies
• The Extended Chandra Deep Field-South Survey: Optical spectroscopy of faint X-ray sources with the VLT and Keck
• The XMM Deep survey in the CDFS I. First results on heavily obscured AGN
• The Chandra COSMOS-Legacy survey: Source X-ray spectral properties
• Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs). X. Discovery of 35 Quasars and Luminous Galaxies at 5.7 $\le$ z $\le$ 7.0
• The Multiwavelength Survey by Yale-Chile (MUSYC): Deep Near-Infrared Imaging and the Selection of Distant Galaxies
• The Environments of High Redshift QSOs
• The Hard X-Ray Luminosity Function of High-Redshift ($3<z\lesssim 5$) Active Galactic Nuclei
• Evidence for Primordial Clustering Around the QSO SDSS J1030+0524 at z=6.28
• The primordial environment of super massive black holes: large scale galaxy overdensities around $z\sim 6$ QSOs with LBT
• The Chandra COSMOS Legacy Survey: Compton Thick AGN at high redshift
• The XMM deep survey in the CDFS IV. Candidate Compton-thick AGN
• The Chandra Deep Protocluster Survey: Point-Source Catalogs for a 400 ks Observation of the z = 3.09 Protocluster in SSA22
• The Multiwavelength Survey by Yale-Chile (MUSYC): Wide K-band Imaging, Photometric Catalogs, Clustering and Physical Properties of Galaxies at z~2
• AGN Populations in Large Volume X-ray Surveys: Photometric Redshifts and Population Types found in the Stripe 82X Survey
• QSO obscuration at high redshift ($z\gtrsim 7$): Predictions from the BlueTides simulation
• Photometry and Photometric Redshift catalogs for the Lockman Hole Deep Field
• The web of the Giant: spectroscopic confirmation of a Large Scale Structure around the z=6.31 quasar SDSS J1030+0524
• The primordial environment of supermassive black holes (II): deep Y and J band images around the z=6.3 quasar SDSS J1030+0524
• Finding Rare AGN: X-ray Number Counts of Chandra Sources in Stripe 82
• The deep Chandra survey in the SDSS J1030+0524 field
• The XMM deep survey in the CDFS XI. X-ray properties of 185 bright sources

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