The Infrared Medium-deep Survey. VI. Discovery of Faint Quasars at $z\sim 5$ with a Medium-band-based Approach

Abstract

The faint quasars with $M_{1450}>-24$ mag are known to hold the key to the determination of the ultraviolet emissivity for the cosmic re-ionization. But only a few have been identified so far because of the limitations on the survey data. Here, we present the first results of the $z\sim 5$ faint quasar survey with the Infrared Medium-deep Survey (IMS), which covers $\sim 100$ deg${}^2$ areas in $J$-band to the depths of $J_{\mathrm{AB}}\sim 23$ mag. To improve selection methods, the medium-band follow-up imaging has been carried out using the SED camera for QUasars in Early uNiverse (SQUEAN) on the Otto Struve 2.1 m Telescope. The optical spectra of the candidates were obtained with 8-m class telescopes. We newly discovered 10 quasars with $-25<M_{1450}<-23$ at $z\sim 5$, among which three have been missed in a previous survey using the same optical data over the same area, implying the necessity for improvements in high redshift faint quasars selection. We derived photometric redshifts from the medium-band data, and find that they have high accuracies of $⟨|\Delta z|/(1+z)⟩=0.016$. The medium-band-based approach allows us to rule out many of the interlopers that contaminate $\gtrsim 20\%$ of the broad-band-selected quasar candidates. These results suggest that the medium-band-based approach is a powerful way to identify $z\sim 5$ quasars and measure their redshifts at high accuracy (1-2 %). It is also a cost-effective way to understand the contribution of quasars to the cosmic re-ionization history.

arXiv comment24 pages, 9 figures, 6 tables. Accepted for publication in ApJ

References in corpus (76)

• Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD
• The UKIRT Infrared Deep Sky Survey (UKIDSS)
• High Redshift Galaxies in the Hubble Deep Field. Color Selection and Star Formation History to z=4
• Composite Quasar Spectra From the Sloan Digital Sky Survey
• A Catalog of Quasar Properties from SDSS DR7
• A luminous quasar at a redshift of z = 7.085
• Constraining the Evolution of the Ionizing Background and the Epoch of Reionization with z ~ 6 Quasars II: A Sample of 19 Quasars
• Radiative transfer in a clumpy universe: IV. New synthesis models of the cosmic UV/X-ray background
• An 800-million-solar-mass black hole in a significantly neutral Universe at redshift 7.5
• 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
• Cosmic Reionization and Early Star-Forming Galaxies: A Joint Analysis of New Constraints from Planck and Hubble Space Telescope
• The SDSS Quasar Survey: Quasar Luminosity Function from Data Release Three
• The UKIRT Infrared Deep Sky Survey ZYJHK Photometric System: Passbands and Synthetic Colours
• An ultra-luminous quasar with a twelve-billion-solar-mass black hole at redshift 6.30
• New Constraints on Cosmic Reionization from the 2012 Hubble Ultra Deep Field Campaign
• The Canada-France High-z Quasar Survey: nine new quasars and the luminosity function at redshift 6
• The Sloan Digital Sky Survey Quasar Catalog: twelfth data release
• Stellar SEDs from 0.3-2.5 Microns: Tracing the Stellar Locus and Searching for Color Outliers in SDSS and 2MASS
• The Pan-STARRS1 distant z>5.6 quasar survey: more than 100 quasars within the first Gyr of the universe
• L and T Dwarf Models and the L to T Transition
• Cosmic Reionization after Planck: Could Quasars Do It All?
• The Final SDSS High-Redshift Quasar Sample of 52 Quasars at z>5.7
• Faint AGNs at z>4 in the CANDELS GOODS-S field: looking for contributors to the reionization of the Universe
• Physical properties of 15 quasars at $z\gtrsim 6.5$
• Discovery of three z>6.5 quasars in the VISTA Kilo-degree Infrared Galaxy (VIKING) survey
• The Multiwavelength Survey by Yale-Chile (MUSYC): Survey Design and Deep Public UBVRIz' Images and Catalogs of the Extended Hubble Deep Field South
• The z~6 Luminosity Function Fainter than -15 mag from the Hubble Frontier Fields: The Impact of Magnification Uncertainties
• Planck intermediate results. XLVII. Planck constraints on reionization history
• The z=5 Quasar Luminosity Function from SDSS Stripe 82
• The evolution of faint AGN between z~1 and z~5 from the COMBO-17 survey
• Subaru high-z exploration of low-luminosity quasars (SHELLQs). I. Discovery of 15 quasars and bright galaxies at 5.7 < z < 6.9
• The Evolution of the Intergalactic Medium Transmission to Redshift Six
• Continuum and Emission Line Strength Relations for a large Active Galactic Nuclei Sample
• The identification of z-dropouts in Pan-STARRS1: three quasars at 6.5<z<6.7
• No evidence for a significant AGN contribution to cosmic hydrogen reionization
• The ALHAMBRA Project: A large area multi medium-band optical and NIR photometric survey
• The CFHT Legacy Survey: stacked images and catalogs
• An X-shooter composite of bright 1 < z < 2 quasars from UV to infrared
• Discovery of eight z ~ 6 quasars from Pan-STARRS1
• Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs). II. Discovery of 32 Quasars and Luminous Galaxies at 5.7 < z < 6.8
• SEDfit: Software for Spectral Energy Distribution Fitting of Photometric Data
• The production and escape of Lyman-Continuum radiation from star-forming galaxies at z~2 and their redshift evolution
• Eight new luminous z > 6 quasars selected via SED model fitting of VISTA, WISE and Dark Energy Survey Year 1 Observations
• The UV Continuum of Quasars: Models and SDSS Spectral Slopes
• The Subaru high-z quasar survey: discovery of faint z~6 quasars
• A survey of luminous high-redshift quasars with SDSS and WISE. I. target selection and optical spectroscopy
• The Faint End of the z=5 Quasar Luminosity Function from the CFHTLS
• On the relative Contribution of high-redshift Galaxies and Active Galactic Nuclei to Reionization
• The Luminosity Function of high-redshift QSOs - A combined analysis of GOODS and SDSS
• The Lyman Continuum escape fraction of faint galaxies at z~3.3 in the CANDELS/GOODS-North, EGS, and COSMOS fields with LBC
• First discoveries of z~6 quasars with the Kilo Degree Survey and VISTA Kilo-Degree Infrared Galaxy survey
• The NEWFIRM Medium-Band Survey: Filter Definitions and First Results
• Constraining the contribution of active galactic nuclei to reionisation
• A survey of luminous high-redshift quasars with SDSS and WISE II. the bright end of the quasar luminosity function at z ~ 5
• Constraining the UV emissivity of AGN throughout cosmic time via X-ray surveys
• Rest-frame Optical Spectra and Black Hole Masses of 3<z<6 Quasars
• The SDSS-2MASS-WISE Ten Dimensional Stellar Color Locus
• A Measurement of the Cosmological Constant Using Elliptical Galaxies as Strong Gravitational Lenses
• Minor Contribution of Quasars to Ionizing Photon Budget at z~6: Update on Quasar Luminosity Function at the Faint-end with Subaru/Suprime-Cam
• On the Evolution of the Cosmic Ionizing Background
• Constraints on the Lyman continuum escape fraction for faint star forming galaxies
• GALEX observations of quasar variability in the ultraviolet
• Discovery of 16 New z ~ 5.5 Quasars : Filling in the Redshift Gap of Quasar Color Selection
• Physical properties of the first quasars
• Discovery of A Faint Quasar at z~6 and Implications for Cosmic Reionization
• Optical Images and Source Catalog of AKARI North Ecliptic Pole Wide Survey Field
• Emission-Line Properties of z > 4 Quasars
• Constraints on the faint end of the quasar luminosity function at z~5 in the COSMOS field
• Camera for QUasars in EArly uNiverse (CQUEAN)
• Quasi-stellar objects in the ALHAMBRA survey. I. Photometric redshift accuracy based on a 23 optical-NIR filter photometry
• The Infrared Medium-deep Survey. IV. Low Eddington Ratio of A Faint Quasar at $z\sim 6$: Not Every Supermassive Black Hole is Growing Fast in the Early Universe
• The ALHAMBRA survey: Discovery of a faint QSO at z = 5.41
• The Infrared Medium-deep Survey. III. Survey of Luminous Quasars at 4.7 $\le$ z $\le$ 5.4
• Auto-Guiding System for CQUEAN (Camera for QUasars in EArly uNiverse)
• An Optically Faint Quasar Survey at z~5 in the CFHTLS Wide Field: Estimates of the Black Hole Masses and Eddington Ratios
• Development of SED Camera for Quasars in Early Universe (SQUEAN)

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• The rapid transition from star-formation to AGN dominated rest-frame UV light at z ~ 4
• Pure Density Evolution of the Ultraviolet Quasar Luminosity Function at $2\lesssim z\lesssim 6$
• The Infrared Medium-deep Survey. \Romannum{7}. Faint Quasars at $z\sim 5$ in the ELAIS-N1 Field
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• High Star Formation Rates of Low Eddington Ratio Quasars at $z\gtrsim 6$
• Eddington Ratios of Dust-obscured Quasars at $z\lesssim 1$: Evidence Supporting Dust-obscured Quasars as Young Quasars
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• High-$z$ Universe probed via Lensing by QSOs (HULQ) I. Number Estimates of QSO-QSO and QSO-Galaxy Lenses
• Medium-band observation of the neutrino emitting blazar, TXS 0506+056
• The quasar luminosity function at $z\sim 5$ via deep learning and Bayesian information criterion
• High-$z$ Universe probed via Lensing by QSOs (HULQ) II. Deep GMOS spectroscopy of a QSO lens candidate