Obscured AGN at z~1 from the zCOSMOS-Bright Survey I. Selection and Optical Properties of a [Ne v]-selected sample

Abstract

A sample of 94 narrow line AGN with 0.65<z<1.20 has been selected from the 20k-Bright zCOSMOS galaxy sample by detection of the high-ionization [NeV]3426 line. Taking advantage of the large amount of data available in the COSMOS field, the properties of the [NeV]-selected Type-2 AGN have been investigated, focusing on their host galaxies, X-ray emission, and optical line flux ratios. Finally, the diagnostic developed by Gilli et al. (2010), based on the X-ray to [NeV] luminosity ratio, has been exploited to search for the more heavily obscured AGN. We found that [Ne v]-selected narrow line AGN have Seyfert 2-like optical spectra, although with emission line ratios diluted by a star-forming component. The ACS morphologies and stellar component in the optical spectra indicate a preference for our Type-2 AGN to be hosted in early-spirals with stellar masses greater than 10^(9.5-10)Msun, on average higher than those of the galaxy parent sample. The fraction of galaxies hosting [NeV]-selected obscured AGN increases with the stellar mass, reaching a maximum of about 3% at 2x10^11 Msun. A comparison with other selection techniques at z~1 shows that the detection of the [Ne v] line is an effective method to select AGN in the optical band, in particular the most heavily obscured ones, but can not provide by itself a complete census of AGN2. Finally, the high fraction of [NeV]-selected Type-2 AGN not detected in medium-deep Chandra observations (67%) is suggestive of the inclusion of Compton-thick sources in our sample. The presence of a population of heavily obscured AGN is corroborated by the X-ray to [NeV] ratio; we estimated, by mean of X-ray stacking technique and simulations, that the Compton-thick fraction in our sample of Type-2 AGN is 43+-4%, in good agreement with standard assumptions by the XRB synthesis models.

arXiv comment14 pages, 12 figures, accepted for publication in A&A

References in corpus (49)

• Stellar population synthesis at the resolution of 2003
• A Fundamental Relation Between Supermassive Black Holes and Their Host Galaxies
• The Demography of Massive Dark Objects in Galaxy Centres
• The Host Galaxies of AGN
• The slope of the black-hole mass versus velocity dispersion correlation
• Composite Quasar Spectra From the Sloan Digital Sky Survey
• Local Supermassive Black Holes, Relics of Active Galactic Nuclei and the X-ray Background
• zCOSMOS: A Large VLT/VIMOS redshift survey covering 0 < z < 3 in the COSMOS field
• The synthesis of the cosmic X-ray background in the Chandra and XMM-Newton era
• The SDSS Quasar Survey: Quasar Luminosity Function from Data Release Three
• The First Release COSMOS Optical and Near-IR Data and Catalog
• The COSMOS Survey: Hubble Space Telescope / Advanced Camera for Surveys (HST/ACS) Observations and Data Processing
• The 2dF QSO Redshift Survey - XII. The spectroscopic catalogue and luminosity function
• COSMOS : Hubble Space Telescope Observations
• zCOSMOS - 10k-bright spectroscopic sample. The bimodality in the Galaxy Stellar Mass Function: exploring its evolution with redshift
• Deep Extragalactic X-ray Surveys
• Black Hole Mass Estimates from Reverberation Mapping and from Spatially Resolved Kinematics
• A Catalog of Detailed Visual Morphological Classifications for 14034 Galaxies in the Sloan Digital Sky Survey
• The Chandra COSMOS Survey, I: Overview and Point Source Catalog
• Semi-empirical analysis of Sloan Digital Sky Survey galaxies III. How to distinguish AGN hosts
• PRIMUS: The dependence of AGN accretion on host stellar mass and color
• Innovations in the Analysis of Chandra-ACIS Observations
• The VIMOS-VLT Deep Survey: Evolution of the galaxy luminosity function up to z=2 in first epoch data
• The Chandra COSMOS Survey: III. Optical and Infrared Identification of X-ray Point Sources
• Ongoing and co-evolving star formation in zCOSMOS galaxies hosting Active Galactic Nuclei
• A New Diagnostic of Active Galactic Nuclei: Revealing Highly-Absorbed Systems at Redshift>0.3
• Tracking the impact of environment on the Galaxy Stellar Mass Function up to z~1 in the 10k zCOSMOS sample
• Galaxy Zoo: The fundamentally different co-evolution of supermassive black holes and their early- and late-type host galaxies
• The VVDS data reduction pipeline: introducing VIPGI, the VIMOS Interactive Pipeline and Graphical Interface
• The Luminosity-Metallicity relation in the local universe from the 2dF Galaxy Redshift Survey
• X-Rays from NGC 3256: High-Energy Emission in Starburst Galaxies and Their Contribution to the Cosmic X-Ray Background
• The Evolution of AGN Host Galaxies: From Blue to Red and the Influence of Large-Scale Structures
• The Evolution of Obscuration in AGN
• Type II Quasars from the Sloan Digital Sky Survey: V. Imaging host galaxies with the Hubble Space Telescope
• EZ: A Tool for Automatic Redshift Measurement
• Spectral classification of emission-line galaxies from the Sloan Digital Sky Survey. I. An improved classification for high redshift galaxies
• New diagnostic methods for emission-line galaxies in deep surveys
• The X-ray to [Ne V]3426 flux ratio: discovering heavily obscured AGN in the distant Universe
• Physical properties of galaxies and their evolution in the VIMOS VLT Deep Survey. I. The evolution of the mass-metallicity relation up to z~0.9
• The zCOSMOS survey: the role of the environment in the evolution of the luminosity function of different galaxy types
• The [OIII] emission line luminosity function of optically selected type-2 AGN from zCOSMOS
• Red and Blue Shifted Broad Lines in Luminous Quasars
• The Chandra survey of the COSMOS field II: source detection and photometry
• The Chandra-COSMOS survey IV: X-ray spectra of the bright sample
• An ionizing UV background dominated by massive stars
• Broad-band colors and overall photometric properties of template galaxy models from stellar population synthesis
• The zCOSMOS redshift survey: the three-dimensional classification cube and bimodality in galaxy physical properties
• The VIMOS VLT Deep Survey: the faint type-1 AGN sample
• Discovery of the high--ionization emission line [Ne V] 3426 in the blue compact dwarf galaxy Tol 1214-277

Cited by in corpus (51)

• Euclid. I. Overview of the Euclid mission
• Obscured Active Galactic Nuclei
• Nuclear activity versus star formation: emission-line diagnostics at ultraviolet and optical wavelengths
• The incidence of obscuration in active galactic nuclei
• Obscuration-dependent evolution of Active Galactic Nuclei
• AGN Emission Line Diagnostics and the Mass-Metallicity Relation up to Redshift z~2: the Impact of Selection Effects and Evolution
• MusE GAs FLOw and Wind (MEGAFLOW) II. A study of gas accretion around $z\approx 1$ star-forming galaxies with background quasars
• Candidate Type II Quasars at 2 < z < 4.3 in the Sloan Digital Sky Survey III
• Compton Thick AGN in the XMM-COSMOS survey
• AGN feedback at z~2 and the mutual evolution of active and inactive galaxies
• Obscured AGN at 1.5 < z < 3.0 from the zCOSMOS-deep Survey I. Properties of the emitting gas in the Narrow Line Region
• SINFONI spectra of heavily obscured AGNs in COSMOS: evidence of outflows in a MIR/O target at z$\sim 2.5$
• Dual supermassive black holes at close separation revealed by the Hyper Suprime-Cam Subaru Strategic Program
• A wide search for obscured Active Galactic Nuclei using XMM-Newton and WISE
• The Chandra Deep Fields: Lifting the Veil on Distant Active Galactic Nuclei and X-Ray Emitting Galaxies
• Coronal-Line Forest AGN: the best view of the inner edge of the AGN torus?
• JADES: The star-formation and chemical enrichment history of a luminous galaxy at z~9.43 probed by ultra-deep JWST/NIRSpec spectroscopy
• Seven wonders of Cosmic Dawn: JWST confirms a high abundance of galaxies and AGNs at z $\simeq$ 9-11 in the GLASS field
• Using [Ne V]/[Ne III] to Understand the Nature of Extreme-Ionization Galaxies
• An obscured AGN population hidden in the VIPERS galaxies: identification through spectral energy distribution decomposition
• Near-infrared emission line diagnostics for AGN from the local Universe to redshift 3
• The Close AGN Reference Survey (CARS): No obvious signature of AGN feedback on star formation, but subtle trends
• CLEAR: High-Ionization [Ne V] $\lambda$3426 Emission-line Galaxies at $1.4<z<2.3$
• On R-W1 as A Diagnostic to Discover Obscured Active Galactic Nuclei in Wide-Area X-ray Surveys
• The VIMOS Public Extragalactic Redshift Survey (VIPERS). AGN feedback in [NeV] emitters
• The space density of Compton-thick AGN at z~0.8 in the zCOSMOS-Bright Survey
• The Geometry of the Infrared and X-ray Obscurer in a Dusty Hyperluminous Quasar
• Narrow line AGN selection in CEERS: spectroscopic selection, physical properties, X-ray and radio analysis
• RXJ0848.6+4453: The Evolution of Galaxy Sizes and Stellar Populations in a z=1.27 Cluster
• A hidden active galactic nucleus powering bright [O III] nebulae in a protocluster at $z=4.5$ revealed by JWST
• Near Infrared Spectra and Intrinsic Luminosities of Candidate Type II Quasars at 2 < z < 3.4
• The OTELO survey. I. Description, data reduction, and multi-wavelength catalogue
• Discovery and origins of giant optical nebulae surrounding quasar PKS 0454-22
• Classifying Intermediate Redshift Galaxies in SDSS: Alternative Diagnostic Diagrams
• KCWI observations of the extended nebulae in Mrk 273
• Heavily Obscured AGN detection: a Radio vs X-ray challenge
• UNCOVERing the High-redshift AGN Population among Extreme UV Line Emitters
• The XMM-Newton Bright Survey sample of absorbed quasars: X-ray and accretion properties
• A Method to improve line flux and redshift measurements with narrowband filters
• COSMOS2020: Investigating the AGN-obscured accretion phase at $z\sim 1$ via [NeV] selection
• Exploring the mysterious high-ionization source powering [Ne V] in high-z analog SBS0335-052 E with JWST/MIRI
• BASS. XLIX. Characterization of highly luminous and obscured AGNs: local X-ray and [NeV]$\lambda$3426 emission in comparison with the high-redshift Universe
• Exploring the Active Galactic Nuclei population with extreme X-ray to optical flux ratios (Fx/Fo >50)
• Identifying type II quasars at intermediate redshift with few-shot learning photometric classification
• X-ray Selected Narrow-Line Active Galactic Nuclei in the COSMOS Field: Nature of Optically Dull Active Galactic Nuclei
• JWST's PEARLS: A z=6 quasar in a train-wreck galaxy merger system
• The Gemini/HST Galaxy Cluster Project: Environment Effects on the Stellar Populations in the Lynx Clusters at z=1.27
• LBT-MODS spectroscopy of high-redshift candidates in the Chandra J1030 field. A newly discovered z$\sim$2.8 large scale structure
• Star Formation Rates in [Ne V] 3426 Å Selected Active Galactic Nuclei: Evidence for a Decrease along the Main Sequence?
• X-ray selection of Compton Thick AGN at high redshift
• Shocks and complex chemodynamics in the metal-poor starburst galaxy CGCG 007-025 revealed through high-resolution echelle spectroscopy