Related papers: Luminous K-band Selected Quasars from UKIDSS

The results of a large area, ~600 deg^2, K-band flux-limited spectroscopic survey for luminous quasars are presented. The survey utilises the UKIRT Infrared Deep Sky Survey (UKIDSS) Large Area Survey (LAS) in regions of sky within the Sloan…

Spectra of nearly 20000 point-like objects to a Galactic reddening corrected magnitude of i=19.1 have been obtained to test the completeness of the SDSS quasar survey. The spatially-unresolved objects were selected from all regions of color…

We present the results of a pilot survey to find dust-reddened quasars by matching the FIRST radio catalog to the UKIDSS near-infrared survey, and using optical data from SDSS to select objects with very red colors. The deep K-band limit…

Combining radio observations with optical and infrared color selection -- demonstrated in our pilot study to be an efficient selection algorithm for finding red quasars -- we have obtained optical and infrared spectroscopy for 120 objects…

In this paper we present preliminary spectroscopic results from a small area faint K-excess (KX) survey, and compare KX selection against UVX selection. The aim of the KX method is to produce complete samples of QSOs flux-limited in the K…

The longstanding question of the extent to which the quasar population is affected by dust extinction, within host galaxies or galaxies along the line of sight, remains open. More generally, the spectral energy distributions of quasars vary…

We present a new sample of purely near infra-red selected KVega<16.5 extremely red ((J-K)>2.5) quasar candidates at z~2 from 900 sq deg of data in the UKIDSS Large Area Survey (LAS). Five of these are spectroscopically confirmed to be…

We present a new sample of 35 quasars selected from the FIRST radio survey and the Deeprange I-band survey (Postman et al. 1998, 2002). A comparison with the FIRST Bright Quasar survey samples reveals that this I-band selected sample is…

Quasi-stellar objects (QSOs) whose spectral energy distributions (SEDs) are reddened by dust either in their host galaxies or in intervening absorber galaxies are to a large degree missed by optical color selection criteria like the one…

We conducted an exploratory search for quasars at z~ 6 - 8, using the Early Data Release from United Kingdom Infrared Deep Sky survey (UKIDSS) cross-matched to panoramic optical imagery. High redshift quasar candidates are chosen using…

We have constructed a sample of bright near-infrared sources which are detected at radio wavelengths but undetected on the POSS I plates in order to search for a population of dust-obscured quasars. Optical and infrared spectroscopic…

We present an investigation of quasar colour-redshift parameter space in order to search for radio-quiet red quasars and to test the ability of a variant of the KX quasar selection method to detect quasars over a full range of colour…

AIMS: We present a sample of candidate quasars selected using the KX-technique. The data cover 0.68 deg^2 of the X-ray Multi-Mirror (XMM) Large-Scale Structure (LSS) survey area where overlapping multi-wavelength imaging data permits an…

We have undertaken a pilot survey for faint QSOs in the UKIDSS Ultra Deep Survey Field using the KX selection technique. These observations exploit the very deep near-infrared and optical imaging of this field from UKIRT and Subaru to…

We present a catalog of over 130,000 quasars candidates with NIR photometric properties, with an areal coverage of approximately 1,200 deg^2. This is achieved by matching the Sloan Digital Sky Survey (SDSS) in the optical ugriz bands, to…

The sub-population of quasars reddened by intrinsic or intervening clouds of dust are known to be underrepresented in optical quasar surveys. By defining a complete parent sample of the brightest and spatially unresolved quasars in the…

We present a sample of 8498 quasars with both SDSS $ugriz$ optical and UKIDSS $YJHK$ near-IR photometric data. With this sample, we obtain the median colour-z relations based on 7400 quasars with magnitude uncertainties less than 0.1mag in…

In order to find the most extreme dust-hidden high-redshift galaxies, we select 196 extremely red objects in the Ks and IRAC bands (KIEROs, [Ks-4.5um](AB)>1.6) in the 0.06 deg^2 GOODS-N region. This selection avoids the Balmer breaks of…

Identifications of quasars at intermediate redshifts (2.2<z<3.5) are inefficient in most previous quasar surveys as their optical colors are similar to those of stars. The near-IR K-band excess technique has been suggested to overcome this…

We present short \chandra observations of twelve bright (i<18) z_em~1.5 quasars from the Sloan Digital Sky Survey chosen to have significantly redder optical colors than most quasars at the same redshift. Of the five quasars with optical…