The discovery of the first luminous z~6 quasar in the UKIDSS Large Area Survey

Abstract

We present the initial results from our search for high redshift, z > 6, quasars using near infrared data from the UKIRT Infrared Deep Sky Survey (UKIDSS) Large Area Survey (LAS). Our analysis of 106 deg^2 of sky from Data Release 1 (DR1) has resulted in the discovery of ULAS J020332.38+001229.2, a luminous (J_AB=20.0, J_Vega=19.1, M_1450=-26.2) quasar at z=5.86. Following candidate selection from the combined IR and optical catalogue data and stacking of multiple epoch Sloan Digital Sky Survey (SDSS) data, we have obtained optical spectroscopy for the only two z > 6 quasar candidates. The VLT FORS2 spectrum of ULAS J020332.38+001229.2 shows broad Ly alpha + NV1240 emission at ~8350 A and an abrupt continuum break due to absorption by the Ly alpha forest. The quasar is not present in the SDSS DR5 catalogue and the continuum spectral index of alpha=-1.4 (F_nu nu^alpha) is redder than a composite of SDSS quasars at similar redshifts (alpha=-0.5). The discovery of one z~6 quasar in ~100 deg^2 in a complete sample within our selection criteria down to a median depth of Y_AB=20.4 (7 sigma) is consistent with existing SDSS results. We describe our survey methodology, including the use of optical data from the SDSS and the highly effective procedures developed to isolate the very small surface density of high-probability quasar candidates.

5 pages, 4 figures. Accepted by MNRAS Letters. v2: small changes to match accepted version

References in corpus (1)

• The UKIRT Infrared Deep Sky Survey Early Data Release

Cited by in corpus (35)

• The UKIRT Infrared Deep Sky Survey (UKIDSS)
• The WFCAM Science Archive
• The Pan-STARRS1 distant z>5.6 quasar survey: more than 100 quasars within the first Gyr of the universe
• The Final SDSS High-Redshift Quasar Sample of 52 Quasars at z>5.7
• Physical properties of 15 quasars at $z\gtrsim 6.5$
• Black hole masses and enrichment of z ~ 6 SDSS quasars
• A Survey of z~6 Quasars in the SDSS Deep Stripe: I. a Flux-Limited Sample at z_{AB}<21
• Thermal Emission from Warm Dust in the Most Distant Quasars
• A downturn in intergalactic CIV as redshift 6 is approached
• A very cool brown dwarf in UKIDSS DR1
• Discovery of eight z ~ 6 quasars from Pan-STARRS1
• Six more quasars at redshift 6 discovered by the Canada-France High-z Quasar Survey
• 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
• The Subaru high-z quasar survey: discovery of faint z~6 quasars
• LCDM predictions for galaxy protoclusters I: the relation between galaxies, protoclusters and quasars at z~6
• SPACE: the SPectroscopic All-sky Cosmic Explorer
• No evidence for [CII] halos or high-velocity outflows in z>6 quasar host galaxies
• New Constraints on Quasar Evolution: Broad Line Velocity Shifts over $1.5\lesssim z\lesssim 7.5$
• Gas dynamics of a luminous $z$ = 6.13 quasar ULAS J1319$+$0950 revealed by ALMA high resolution observations
• Discovery of Eight z ~ 6 Quasars in the Sloan Digital Sky Survey Overlap Regions
• Quasar UV luminosity function evolution up to z=8
• Comprehensive Gas Characterization of a $z=2.5$ Protocluster: A Cluster Core Caught in the Beginning of Virialization?
• A closer look at using quasar near-zones as a probe of neutral hydrogen in the intergalactic medium
• Infrared emission of $z\sim 6$ galaxies: AGN imprints
• Combining Dark Energy Survey Science Verification Data with Near Infrared Data from the ESO VISTA Hemisphere Survey
• The Pan-STARRS1 $\mathbf{z}>5.6$ Quasar Survey: III. The $\mathbf{z}\approx 6$ Quasar Luminosity Function
• Constraining galaxy overdensities around three z~6.5 quasars with ALMA and MUSE
• Limits to Rest-Frame Ultraviolet Emission From Far-Infrared-Luminous z~6 Quasar Hosts
• The Extremely Luminous Quasar Survey in the Pan-STARRS 1 Footprint (PS-ELQS)
• SCUBA2 High Redshift Bright Quasar Survey: Far-infrared Properties and Weak-line Features
• Four Faint T Dwarfs from the UKIRT Infrared Deep Sky Survey (UKIDSS) Southern Stripe
• A lack of LAEs within 5Mpc of a luminous quasar in an overdensity at z=6.9: potential evidence of quasar negative feedback at protocluster scales
• An Exploratory Search for z~6 Quasars in the UKIDSS Early Data Release
• Effects of the Hubble Parameter on the Cosmic Growth of the First Quasars
• Euclid preparation. Exploring the properties of proto-clusters in the Simulated Euclid Wide Survey