The Spitzer mid-infrared AGN survey. I - optical and near-infrared spectroscopy of candidate obscured and normal AGN selected in the mid-infrared

Abstract

We present the results of a program of optical and near-infrared spectroscopic follow-up of candidate Active Galactic Nuclei (AGN) selected in the mid-infrared. This survey selects both normal and obscured AGN closely matched in luminosity across a wide range, from Seyfert galaxies with bolometric luminosities L_bol~10^10L_sun, to highly luminous quasars (L_bol~10^14L_sun), and with redshifts from 0-4.3. Samples of candidate AGN were selected through mid-infrared color cuts at several different 24 micron flux density limits to ensure a range of luminosities at a given redshift. The survey consists of 786 candidate AGN and quasars, of which 672 have spectroscopic redshifts and classifications. Of these, 137 (20%) are type-1 AGN with blue continua, 294 (44%) are type-2 objects with extinctions A_V>~5 towards their AGN, 96 (14%) are AGN with lower extinctions (A_V~1) and 145 (22%) have redshifts, but no clear signs of AGN activity in their spectra. 50% of the survey objects have L_bol >10^12L_sun, in the quasar regime. We present composite spectra for type-2 quasars and for objects with no signs of AGN activity in their spectra. We also discuss the mid-infrared - emission-line luminosity correlation and present the results of cross-correlations with serendipitous X-ray and radio sources. The results show that: (1) obscured objects dominate the overall AGN population, (2) there exist mid-infrared selected AGN candidates which lack AGN signatures in their optical spectra, but have AGN-like X-ray or radio counterparts, and (3) X-ray and optical classifications of obscured and unobscured AGN often differ.

arXiv commentApJS, in press

References in corpus (84)

• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• The Seventh Data Release of the Sloan Digital Sky Survey
• The UKIRT Infrared Deep Sky Survey (UKIDSS)
• The 2dF Galaxy Redshift Survey: Spectra and redshifts
• Rest-Frame Ultraviolet Spectra of z~3 Lyman Break Galaxies
• Spectral Energy Distributions and Multiwavelength Selection of Type 1 Quasars
• The 6dF Galaxy Survey: Final Redshift Release (DR3) and Southern Large-Scale Structures
• Mid-Infrared Selection of Active Galaxies
• SWIRE: The SIRTF Wide-area InfraRed Extragalactic Survey
• Obscured and unobscured active galactic nuclei in the Spitzer Space Telescope First Look Survey
• Identifying Luminous AGN in Deep Surveys: Revised IRAC Selection Criteria
• The Spitzer Legacy Survey of the HST-ACS 2 sq. deg. COSMOS Field: survey strategy and first analysis
• The Chandra Source Catalog
• The Las Campanas Redshift Survey
• The XMM-Newton Serendipitous Survey. V. The Second XMM-Newton Serendipitous Source Catalogue
• CANDELS: Constraining the AGN-Merger Connection with Host Morphologies at z~2
• Red and Reddened Quasars in the Sloan Digital Sky Survey
• Major Galaxy Mergers Only Trigger the Most Luminous AGN
• Candidate Type II Quasars from the Sloan Digital Sky Survey: I. Selection and Optical Properties of a Sample at 0.3<Z<0.83
• The FIRST Bright Quasar Survey. II. 60 Nights and 1200 Spectra Later
• The VISTA Deep Extragalactic Observations (VIDEO) Survey
• The Far- and Mid-Infrared/Radio Correlations in the Spitzer Extragalactic First Look Survey
• Space density of optically-selected type 2 quasars
• Evidence for Quasar Activity Triggered by Galaxy Mergers in HST Observations of Dust-reddened Quasars
• A Classic Type 2 QSO
• Signals from the Noise: Image Stacking for Quasars in the FIRST Survey
• Optical spectroscopy and X-ray detections of a sample of quasars and AGN selected in the mid-infrared from two Spitzer wide-area surveys
• Radio imaging of the Subaru/XMM-Newton Deep Field - I. The 100-microJy catalogue, optical identifications, and the nature of the faint radio source population
• Observations of Feedback from Radio-Quiet Quasars: I. Extents and Morphologies of Ionized Gas Nebulae
• Deep ATLAS radio observations of the CDFS-SWIRE field
• The obscuration by dust of most of the growth of supermassive black holes
• Spitzer Mid-Infrared Spectroscopy of Infrared Luminous Galaxies at z~2 I: the Spectra
• The CFHT Legacy Survey: stacked images and catalogs
• Spitzer Observations of 3C Quasars and Radio Galaxies: Mid-Infrared Properties of Powerful Radio Sources
• The FIRST-2MASS Red Quasar Survey II: An anomalously high fraction of LoBALs in searches for dust-reddened quasars
• Spitzer Reveals Hidden Quasar Nuclei in Some Powerful FR II Radio Galaxies
• The FIRST-2MASS Red Quasar Survey
• Unveiling a Population of X-ray Non-Detected AGN
• Deep multi-frequency radio imaging in the Lockman Hole using the GMRT and VLA: I. The nature of the sub-mJy radio population
• Spectral energy distributions and luminosities of galaxies and AGN in the SPITZER SWIRE Legacy Survey
• The Reddest Quasars
• Magellan Spectroscopy of AGN Candidates in the COSMOS Field
• The Two-Component Radio Luminosity Function of QSOs: Star Formation and AGN
• Radio imaging of the Subaru/XMM-Newton Deep Field - III. Evolution of the radio luminosity function beyond z=1
• XMM-Newton observations expose AGN in apparently normal galaxies
• The Infrared Array Camera component of the Spitzer Space Telescope Extragalactic First Look Survey
• FIRST-2MASS Sources Below the APM Detection Threshold: A Population of Highly Reddened Quasars
• A population of high-redshift type-2 quasars-I. Selection Criteria and Optical Spectra
• The Spitzer Space Telescope Extra-Galactic First Look Survey: 24 micron data reduction, catalog, and source identification
• A Deep VLA survey at 20cm of the ISO ELAIS survey regions
• Simulating the Spitzer mid-IR color-color diagrams
• Spitzer Observations of Young Red Quasars
• The 1<z<5 Infrared Luminosity Function of Type I Quasars
• An XMM-Newton spectral survey of 12 micron selected galaxies. II. Implications for AGN selection and unification
• Large amounts of optically-obscured star formation in the host galaxies of some type-2 quasars
• Mid-Infrared Diagnostics of LINERs
• Revealing X-ray obscured quasars in SWIRE sources with extreme mid-IR/optical flux ratios
• IR-derived covering factors for a large sample of quasars from WISE-UKIDSS-SDSS
• A Chandra X-Ray Survey of Ultraluminous Infrared Galaxies
• The Molonglo Southern 4 Jy sample (MS4). II. ATCA imaging and optical identification
• Mid-infrared spectroscopy of candidate AGN-dominated submillimeter galaxies
• Stellar Populations in the Host Galaxies of Mrk 1014, IRAS 07598+6508, and Mrk 231
• The nature of the mid-infrared population from optical identifications of the ELAIS-S1 sample
• A MMT/Hectospec Redshift Survey of 24 Micron Sources in the Spitzer First Look Survey
• The ESO-Spitzer Imaging extragalactic Survey (ESIS) I: WFI B,V,R deep observations of ELAIS-S1 and comparison to Spitzer and GALEX data
• Red synchrotron jets in Parkes quasars
• The Australia Telescope Large Area Survey: Spectroscopic Catalogue and Radio Luminosity Functions
• The Reddest Quasars II. A gravitationally-lensed FeLoBAL quasar
• Near- and mid-infrared photometry of high-redshift 3CR sources
• Jet and Torus Orientations in High Redshift Radio Galaxies
• The European Large Area ISO Survey IV: the preliminary 90 micron luminosity function
• AEGIS: Radio and Mid-Infrared Selection of Obscured AGN Candidates
• Spectroscopic Survey of 1.4 GHz and 24 Micron Sources in the Spitzer First Look Survey with WIYN/Hydra
• The cosmological consequence of an obscured AGN population on the radiation efficiency
• The Redshift Distribution of FIRST Radio Sources at 1 mJy
• Obscured and powerful AGN and starburst activities at z~3.5
• Reddening-Independent Quasar Selection from a Wide-Field Optical and Near-IR Imaging Survey
• Optical identification of ISO far-infrared sources in the Lockman Hole using a deep VLA 1.4 GHz continuum survey
• The forbidden high ionisation line region of the type 2 quasar Q1131+16: a clear view of the inner face of the torus?
• The European Large Area ISO Survey VI - Discovery of a new hyperluminous infrared galaxy
• Mid-infrared sources in the ELAIS Deep X-ray Survey
• FIRBACK IV: Towards the nature of the 170microns source population
• The stellar, molecular gas and dust content of the host galaxies of two z~2.8 dust obscured quasars
• A population of extreme mid-to-near-infrared sources: obscured AGN and dusty starbursts

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• Updated measurements of the dark matter halo masses of obscured quasars with improved WISE and Planck data
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• What makes red quasars red? Observational evidence for dust extinction from line ratio analysis
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• A Large Population of Luminous Active Galactic Nuclei Lacking X-ray Detections: Evidence for Heavy Obscuration?
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• High-resolution VLA Imaging of Obscured Quasars: Young Radio Jets Caught in a Dense ISM
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• Near Infrared Spectra and Intrinsic Luminosities of Candidate Type II Quasars at 2 < z < 3.4
• Host Dark Matter Halos of WISE-selected Obscured & Unobscured Quasars: Evidence for Evolution
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• Does AGN Fraction Depend on Redshift or Luminosity? An Extinction-Free Test by 18-band Mid-infrared SED Fitting in the AKARI NEP Wide Field
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• The Star-Formation Properties of the Observed and Simulated AGN Universe: BAT vs EAGLE
• Selection of AGN candidates in the GOODS-South Field through SPITZER/MIPS 24 $\mu$m variability
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• The optical vs. mid-infrared spectral properties of 82 Type 1 AGNs: coevolution of AGN and starburst
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