Probabilistic selection of high-redshift quasars

  title={Probabilistic selection of high-redshift quasars},
  author={Daniel J. Mortlock and Mitesh Patel and Stephen J. Warren and Paul C. Hewett and Bram P. Venemans and Richard G. McMahon and Chris J. Simpson Imperial College London and University of Cambridge and European Southern Observatory and Liverpool John Moores University},
  journal={Monthly Notices of the Royal Astronomical Society},
High-redshift quasars (HZQs) with redshifts of z ≳ 6 are so rare that any photometrically selected sample of sources with HZQ-like colours is likely to be dominated by Galactic stars and brown dwarfs scattered from the stellar locus. It is impractical to re-observe all such candidates, so an alternative approach was developed in which Bayesian model comparison techniques are used to calculate the probability that a candidate is a HZQ, Pq, by combining models of the quasar and star populations… 
High-redshift quasar selection from the CFHQSIR survey
Being observed only one billion years after the Big Bang, z ∼ 7 quasars are a unique opportunity for exploring the early Universe. However, only two z ∼ 7 quasars have been discovered in
Finding the Most Distant Quasars Using Bayesian Selection Methods
Quasars, the brightly glowing disks of material that can form around the super-massive black holes at the centres of large galaxies, are amongst the most luminous astronomical objects known and so
First results from high redshift quasar searches in VIKING
This thesis presents the discovery of the first luminous z & 6.5 quasars in the VISTA kilo-degree Infrared Galaxy Survey (VIKING). After some basic quality control, quasar selection is investigated
Photometric Redshifts and Quasar Probabilities from a Single, Data-driven Generative Model
We describe a technique for simultaneously classifying and estimating the redshift of quasars. It can separate quasars from stars in arbitrary redshift ranges, estimate full posterior distribution
Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs). II. Discovery of 32 quasars and luminous galaxies at 5.7 < z ≤ 6.8
We present spectroscopic identification of 32 new quasars and luminous galaxies discovered at 5.7<z≤6.8. This is the second in a series of papers presenting the results of the Subaru High-z
Discovery of Eight z ~ 6 Quasars in the Sloan Digital Sky Survey Overlap Regions
We present the discovery of eight quasars at z~6 identified in the Sloan Digital Sky Survey (SDSS) overlap regions. Individual SDSS imaging runs have some overlap with each other, leading to repeat
The discovery of eight z ~ 6 quasars from Pan-STARRS1
Abstract High-redshift quasars are unique probes of the evolution of supermassive black holes and the intergalactic medium at the end of the epoch of reionization. We present the optical spectra of
Modelling type 1 quasar colours in the era of Rubin and Euclid
We construct a parametric SED model which is able to reproduce the average observed SDSS–UKIDSS–WISE quasar colours to within one-tenth of a magnitude across a wide range of redshift (0 < z < 5)
A complete search for redshift z ≳ 6.5 quasars in the VIKING survey
We present the results of a new, deeper, and complete search for high-redshift 6.5 < z < 9.3 quasars over 977 deg2 of the VISTA Kilo-Degree Infrared Galaxy (VIKING) survey. This exploits a new
Random Forests as a Viable Method to Select and Discover High-redshift Quasars
It is argued that random forests can lead to higher completeness because the candidate set contains a number of objects that would be rejected by common color cuts, including one of the newly discovered redshift 5.7 quasars.


Luminous K-band Selected Quasars from UKIDSS
The largest K-band flux-limited sample of luminous quasars to date has been constructed from the UKIRT (UK Infrared Telescope) Infrared Deep Sky Survey (UKIDSS) Large Area Survey Early Data Release,
Think outside the color box: Probabilistic target selection and the SDSS-XDQSO quasar targeting catalog
We present the SDSS-XDQSO quasar targeting catalog for efficient flux-based quasar target selection down to the faint limit of the Sloan Digital Sky Survey (SDSS) catalog, even at medium redshifts
The discovery of the first luminous z∼ 6 quasar in the UKIDSS Large Area Survey
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
Efficient Photometric Selection of Quasars from the Sloan Digital Sky Survey: II. ~1,000,000 Quasars from Data Release Six
We present a catalog of 1,172,157 quasar candidates selected from the photometric imaging data of the Sloan Digital Sky Survey (SDSS). The objects are all point sources to a limiting magnitude of
Discovery of a redshift 6.13 quasar in the UKIRT Infrared Deep Sky Survey
Optical and near-infrared (NIR) spectra are presented for ULAS J131911.29+095051.4 (hereafter ULAS J1319+0950), a new redshift z = 6.127 ± 0.004 quasar discovered in the Third Data Release (DR3) of
We conducted an exploratory search for quasars at z ~ 6-8, using the Early Data Release (EDR) from the United Kingdom Infrared Deep Sky Survey (UKIDSS) cross-matched to panoramic optical imagery.
Four Quasars above Redshift 6 Discovered by the Canada-France High-z Quasar Survey
The Canada-France High-z Quasar Survey (CFHQS) is an optical survey designed to locate quasars during the epoch of reionization. In this paper we present the discovery of the first four CFHQS quasars
Redshifted 21‐cm observations of high‐redshift quasar proximity zones
The introduction of low-frequency radio arrays is expected to revolutionize the study of the reionization epoch. Observation of the contrast in redshifted 21-cm emission between a large H II region
We present discovery imaging and spectroscopy for nine new z ∼ 6 quasars found in the Canada–France High-z Quasar Survey (CFHQS) bringing the total number of CFHQS quasars to 19. By combining the
Discovery of a new high-redshift QSO at z = 5.96 with the Subaru Telescope
We report the discovery of a new high-redshift quasar at z = 5.96, observed with the long-slit Faint Object Camera and Spectrograph on board the Subaru Telescope. The spectrum shows strong and broad