Three new VHS-DES Quasars at 6.7 < z < 6.9 and Emission Line Properties at z > 6.5

Abstract

We report the results from a search for z > 6.5 quasars using the Dark Energy Survey (DES) Year 3 dataset combined with the VISTA Hemisphere Survey (VHS) and WISE All-Sky Survey. Our photometric selection method is shown to be highly efficient in identifying clean samples of high-redshift quasars leading to spectroscopic confirmation of three new quasars - VDESJ 0244-5008 (z=6.724), VDESJ 0020-3653 (z=6.834) and VDESJ 0246-5219 (z=6.90) - which were selected as the highest priority candidates in the survey data without any need for additional follow-up observations. The new quasars span the full range in luminosity covered by other z>6.5 quasar samples (J AB = 20.2 to 21.3; M1450 = -25.6 to -26.6). We have obtained spectroscopic observations in the near infrared for VDESJ 0244-5008 and VDESJ 0020-3653 as well as our previously identified quasar, VDESJ 0224-4711 at z=6.50 from Reed et al. (2017). We use the near infrared spectra to derive virial black-hole masses from the full-width-half-maximum of the MgII line. These black-hole masses are ~ 1 - 2 x 10${}^9$M${}_{\odot }$. Combining with the bolometric luminosities of these quasars of L${}_{\mathrm{bol}}\simeq$ 1 - 3 x 10${}^{47}$implies that the Eddington ratios are high - $\simeq$0.6-1.1. We consider the C\textrm{\textsc{IV}} emission line properties of the sample and demonstrate that our high-redshift quasars do not have unusual C\textrm{\textsc{IV}} line properties when compared to carefully matched low-redshift samples. Our new DES+VHS $z>6.5$ quasars now add to the growing census of luminous, rapidly accreting supermassive black-holes seen well into the epoch of reionisation.

arXiv comment12 pages, 9 figures

References in corpus (47)

• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• Cosmic-Ray Rejection by Laplacian Edge Detection
• A Catalog of Quasar Properties from SDSS DR7
• 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
• Spectroscopic Target Selection in the Sloan Digital Sky Survey: The Quasar Sample
• Observational constraints on Cosmic Reionization
• Formation of Supermassive Black Holes
• Optimal Techniques in Two-dimensional Spectroscopy: Background Subtraction for the 21st Century
• An Empirical Ultraviolet Template for Iron Emission in Quasars as Derived from I Zw 1
• The Canada-France High-z Quasar Survey: nine new quasars and the luminosity function at redshift 6
• The Dark Energy Survey Data Release 1
• Unification of Luminous Type 1 Quasars through CIV Emission
• The First Hundred Brown Dwarfs Discovered by the Wide-field Infrared Survey Explorer (WISE)
• Mass Functions of the Active Black Holes in Distant Quasars from the Large Bright Quasar Survey, the Bright Quasar Survey, and the Color-Selected Sample of the SDSS Fall Equatorial Stripe
• 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 $z\gtrsim 6.5$
• An atmospheric radiation model for Cerro Paranal. I. The optical spectral range
• Discovery of three z>6.5 quasars in the VISTA Kilo-degree Infrared Galaxy (VIKING) survey
• What controls the C IV line profile in active galactic nuclei?
• Black hole formation in the early universe
• Evidence for non-evolving FeII/MgII ratios in rapidly accreting z~6 QSOs
• Black hole mass estimates and emission-line properties of a sample of redshift z>6.5 quasars
• An advanced scattered moonlight model for Cerro Paranal
• Bright [CII] and dust emission in three z>6.6 quasar host galaxies observed by ALMA
• Correcting CIV-Based Virial Black Hole Masses
• Gemini GNIRS near-infrared spectroscopy of 50 quasars at z>~5.7
• The Sloan Digital Sky Survey Reverberation Mapping Project: Velocity Shifts of Quasar Emission Lines
• The identification of z-dropouts in Pan-STARRS1: three quasars at 6.5<z<6.7
• Growing the first bright quasars in cosmological simulations of structure formation
• The nature and evolution of the highly ionized near-zones in the absorption spectra of z~6 quasars
• Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs). II. Discovery of 32 Quasars and Luminous Galaxies at 5.7 < z < 6.8
• Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs). IV. Discovery of 41 Quasars and Luminous Galaxies at 5.7 < z < 6.9
• Eight new luminous z > 6 quasars selected via SED model fitting of VISTA, WISE and Dark Energy Survey Year 1 Observations
• Exploring Reionization-Era Quasars IV: Discovery of Six New $z\gtrsim 6.5$ Quasars with DES, VHS and unWISE Photometry
• CIV Emission Line Properties and Systematic Trends in Quasar Black Hole Mass Estimates
• XQ-100: A legacy survey of one hundred 3.5 < z < 4.5 quasars observed with VLT/XSHOOTER
• Deep Full-sky Coadds from Three Years of WISE and NEOWISE Observations
• First discoveries of z~6 quasars with the Kilo Degree Survey and VISTA Kilo-Degree Infrared Galaxy survey
• First Discoveries of z>6 Quasars with the DECam Legacy Survey and UKIRT Hemisphere Survey
• Iron and alpha-element Production in the First One Billion Years after the Big Bang
• The large area KX quasar catalogue: I. Analysis of the photometric redshift selection and the complete quasar catalogue
• Photometric brown-dwarf classification. I. A method to identify and accurately classify large samples of brown dwarfs without spectroscopy
• Combining Dark Energy Survey Science Verification Data with Near Infrared Data from the ESO VISTA Hemisphere Survey
• A new bright z=6.82 quasar discovered with VISTA: VHS J0411-0907
• Simulating Wide-Field Quasar Surveys from the Optical to Near-Infrared

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• Can X-ray Observations Improve Optical-UV-based Accretion-Rate Estimates for Quasars?