The Extremely Luminous Quasar Survey in the Sloan Digital Sky Survey footprint. III. The South Galactic Cap Sample and the Quasar Luminosity Function at Cosmic Noon

Abstract

We have designed the Extremely Luminous Quasar Survey (ELQS) to provide a highly complete census of unobscured UV-bright quasars during the cosmic noon, $z=2.8-5.0$. Here we report the discovery of 70 new quasars in the ELQS South Galactic Cap (ELQS-S) quasar sample, doubling the number of known extremely luminous quasars in $4,237.3{\mathrm{deg}}^2$ of the SDSS footprint. These observations conclude the ELQS and we present the properties of the full ELQS quasar catalog, containing 407 quasars over $11,838.5{\mathrm{deg}}^2$. Our novel ELQS quasar selection strategy resulted in unprecedented completeness at the bright end and allowed us to discover 109 new quasars in total. This marks an increase of $\sim 36\%$ (109/298) to the known population at these redshifts and magnitudes, while we further are able to retain a selection efficiency of $\sim 80\%$. On the basis of 166 quasars from the full ELQS quasar catalog, who adhere to the uniform criteria of the 2MASS point source catalog, we measure the bright-end quasar luminosity function (QLF) and extend it one magnitude brighter than previous studies. Assuming a single power law with exponential density evolution for the functional form of the QLF, we retrieve the best fit parameters from a maximum likelihood analysis. We find a steep bright-end slope of $\beta \approx -4.1$ and we can constrain the bright-end slope to $\beta \le -3.4$ with $99\%$ confidence. The density is well modeled by the exponential redshift evolution, resulting in a moderate decrease with redshift ($\gamma \approx -0.4$).

arXiv comment30 pages, 11 figures, ApJ accepted

References in corpus (60)

• Astropy: A Community Python Package for Astronomy
• emcee: The MCMC Hammer
• Planck 2015 results. XIII. Cosmological parameters
• The Sloan Digital Sky Survey: Technical Summary
• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD
• HEALPix -- a Framework for High Resolution Discretization, and Fast Analysis of Data Distributed on the Sphere
• The Seventh Data Release of the Sloan Digital Sky Survey
• Coevolution (Or Not) of Supermassive Black Holes and Host Galaxies
• The Galaxy Evolution Explorer: A Space Ultraviolet Survey Mission
• SDSS-III: Massive Spectroscopic Surveys of the Distant Universe, the Milky Way Galaxy, and Extra-Solar Planetary Systems
• The Baryon Oscillation Spectroscopic Survey of SDSS-III
• Composite Quasar Spectra From the Sloan Digital Sky Survey
• Sloan Digital Sky Survey IV: Mapping the Milky Way, Nearby Galaxies, and the Distant Universe
• A luminous quasar at a redshift of z = 7.085
• An 800-million-solar-mass black hole in a significantly neutral Universe at redshift 7.5
• The Sloan Digital Sky Survey Quasar Catalog V. Seventh Data Release
• The SDSS Quasar Survey: Quasar Luminosity Function from Data Release Three
• The SDSS-IV extended Baryon Oscillation Spectroscopic Survey: Overview and Early Data
• The 2dF QSO Redshift Survey - I. The Optical QSO Luminosity Function
• The Canada-France High-z Quasar Survey: nine new quasars and the luminosity function at redshift 6
• Second ROSAT all-sky survey (2RXS) source catalogue
• The Sloan Digital Sky Survey Quasar Catalog: Fourteenth Data Release
• The Sloan Digital Sky Survey Quasar Catalog: twelfth data release
• A Catalog of Broad Absorption Line Quasars from the Sloan Digital Sky Survey Third Data Release
• High-Redshift Quasars Found in Sloan Digital Sky Survey Commissioning Data IV: Luminosity Function from the Fall Equatorial Stripe Sampl
• The SDSS Damped Lya Survey: Data Release 3
• Unusual Broad Absorption Line Quasars from the Sloan Digital Sky Survey
• The Final SDSS High-Redshift Quasar Sample of 52 Quasars at z>5.7
• The 2dF-SDSS LRG and QSO Survey: the QSO luminosity function at 0.4<z<2.6
• The Radio-Loud Fraction of Quasars is a Strong Function of Redshift and Optical Luminosity
• A strong redshift dependence of the broad absorption line quasar fraction
• The Distribution of Metallicity in the IGM at z~2.5: OVI and CIV Absorption in the Spectra of 7 QSOs
• The z=5 Quasar Luminosity Function from SDSS Stripe 82
• Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs). V. Quasar Luminosity Function and Contribution to Cosmic Reionization at z = 6
• The SDSS-III Baryon Oscillation Spectroscopic Survey: The Quasar Luminosity Function from Data Release Nine
• A Survey of z~6 Quasars in the SDSS Deep Stripe: I. a Flux-Limited Sample at z_{AB}<21
• Finding counterparts for All-sky X-ray surveys with Nway: a Bayesian algorithm for cross-matching multiple catalogues
• The Half Million Quasars (HMQ) Catalogue
• The Sloan Digital Sky Survey Quasar Lens Search. V. Final Catalog from the Seventh Data Release
• The Faint End of the Quasar Luminosity Function at z~4: Implications for Ionization of the Intergalactic Medium and Cosmic Downsizing
• An improved method of constructing binned luminosity functions
• 2MASS Reveals a Large Intrinsic Fraction of BALQSOs
• Evolution of the Quasar Luminosity Function Over 3 < z < 5 in the COSMOS Survey Field
• Early and Extended Helium Reionization Over More Than 600 Million Years of Cosmic Time
• SDSS quasars in the WISE preliminary data release and quasar candidate selection with optical/infrared colors
• The Extended Baryon Oscillation Spectroscopic Survey: Variability Selection and Quasar Luminosity Function
• The Quasar Luminosity Function at Redshift 4 with Hyper Suprime-Cam Wide Survey
• The Faint End of the z=5 Quasar Luminosity Function from the CFHTLS
• Luminous K-band Selected Quasars from UKIDSS
• A survey of luminous high-redshift quasars with SDSS and WISE II. the bright end of the quasar luminosity function at z ~ 5
• GALEX far-UV color selection of UV-bright high-redshift quasars
• NICMOS and VLA Observations of the Gravitatonally Lensed Ultraluminous BAL Quasar APM~08279+5255: Detection of a Third Image
• Minor Contribution of Quasars to Ionizing Photon Budget at z~6: Update on Quasar Luminosity Function at the Faint-end with Subaru/Suprime-Cam
• Quasar candidate selection and photometric redshift estimation based on SDSS and UKIDSS data
• The Evolution and Luminosity Function of Quasars from Complete Optical Surveys
• Statistical Detection of the HeII Transverse Proximity Effect: Evidence for Sustained Quasar Activity for $>$25 Million Years
• The Extremely Luminous Quasar Survey (ELQS) in the SDSS footprint I.: Infrared Based Candidate Selection
• The Large Sky Area Multi-Object Fibre Spectroscopic Telescope (LAMOST) Quasar Survey: Quasar Properties from Data Release Two and Three
• The Extremely Luminous Quasar Survey (ELQS) in the Sloan Digital Sky Survey footprint. II. The North Galactic Cap Sample

Cited by in corpus (34)

• Evolution of the AGN UV luminosity function from redshift 7.5
• The X-shooter/ALMA Sample of Quasars in the Epoch of Reionization. II. Black Hole Masses, Eddington Ratios, and the Formation of the First Quasars
• Feedback-Dominated Accretion Flows
• The Pan-STARRS1 $\mathbf{z}>5.6$ Quasar Survey: III. The $\mathbf{z}\approx 6$ Quasar Luminosity Function
• On the AGN nature of two UV bright sources at z_spec~5.5 in the CANDELS fields: an update of the AGN space density at M1450~-22.5
• The Infrared Medium-deep Survey. VIII. Quasar Luminosity Function at $z\sim 5$
• The fraction and kinematics of broad absorption line quasars across cosmic time
• The space density of ultra-luminous QSOs at the end of reionization epoch by the QUBRICS Survey and the AGN contribution to the hydrogen ionizing background
• The spectroscopic follow-up of the QUBRICS bright quasar survey
• The Extremely Luminous Quasar Survey in the Pan-STARRS 1 Footprint (PS-ELQS)
• "Little red dots" cannot reside in the same dark matter halos as comparably luminous unobscured quasars
• Ultra-luminous quasars at redshift $z>4.5$ from SkyMapper
• Simulating the infrared sky with a Spritz
• Imaging Polarization of the Blue-Excess Hot Dust-Obscured Galaxy WISE J011601.41-050504.0
• Spectroscopy of QUBRICS quasar candidates: 1672 new redshifts and a Golden Sample for the Sandage Test of the Redshift Drift
• The Probabilistic Random Forest applied to the selection of quasar candidates in the QUBRICS Survey
• Pure Density Evolution of the Ultraviolet Quasar Luminosity Function at $2\lesssim z\lesssim 6$
• The Mass Function of Supermassive Black Holes in the Direct-collapse Scenario
• Ionizing radiation from AGNs at z>3.3 with the Subaru Hyper Suprime-Cam Survey and the CFHT Large Area U-band Deep Survey (CLAUDS)
• AllBRICQS: the All-sky BRIght, Complete Quasar Survey
• Forecasting cosmic acceleration measurements using the Lyman-$\alpha$ forest
• Paving the Way for Euclid and JWST via Optimal Selection of High-z Quasars
• Quasar UV Luminosity Function at $3.5<z<5.0$ from SDSS Deep Imaging Data
• Eddington accreting Black Holes in the Epoch of Reionization
• Spritz is sparkling: simulated CO and [CII] luminosities
• Disentangling the co-evolution of galaxies and supermassive black holes with PRIMA
• A Closer Look at Two of the Most Luminous Quasars in the Universe
• Euclid preparation. Observational expectations for redshift z<7 active galactic nuclei in the Euclid Wide and Deep surveys
• Radio-loudness statistics of quasars from Quaia-VLASS
• The probabilistic random forest applied to the QUBRICS survey: improving the selection of high-redshift quasars with synthetic data
• The PAU Survey: The quasar UV and Ly$\alpha$ luminosity functions at $2.7<z<5.3$
• An Extremely Bright QSO at $z=2.89$
• Estimating the completeness of the QUBRICS Survey with 3501 QSO redshifts from Gaia DR3 spectra
• Ultra-luminous high-redshift quasars from SkyMapper -- II. New quasars and the bright end of the luminosity function