Related papers: Dusty Quasars at High Redshifts

Using ~300,000 photometrically classified quasars, by far the largest quasar sample ever used for such analyses, we study the redshift and luminosity evolution of quasar clustering on scales of ~50 kpc/h to ~20 Mpc/h from redshifts of…

We use photometric data, from the optical to the mm for a large sample of optically selected radio-quiet quasars, at low and high redshifts, to test emission models from circum-nuclear dusty torii around them. Model parameters, such as dust…

We determine the rest-frame 8 micron luminosity function of type I quasars over the redshift range 1<z<5. Our sample consists of 292 24 micron sources brighter than 1 mJy selected from 7.17 square degrees of the Spitzer Space Telescope MIPS…

We identify 885,503 type 1 quasar candidates to i<22 using the combination of optical and mid-IR photometry. Optical photometry is taken from the Sloan Digital Sky Survey-III: Baryon Oscillation Spectroscopic Survey (SDSS-III/BOSS), while…

We present new X-ray observations of luminous heavily dust-reddened quasars (HRQs) selected from infrared sky surveys. HRQs appear to be a dominant population at high redshifts and the highest luminosities, and may be associated with a…

We determine the 22$\mu$m luminosity evolution and luminosity function for quasars from a data set of over 20,000 objects obtained by combining flux-limited Sloan Digital Sky Survey optical and Wide field Infrared Survey Explorer…

The redshift range from 2.2 to 3, is known as the 'redshift desert' of quasars because quasars with redshift in this range have similar optical colors as normal stars and are thus difficult to be found in optical sky surveys. A quasar…

We assemble a catalogue of 488 spectroscopically confirmed very high ($z\geq5.00$) redshift quasars and report their near- ($ZYJHK_{s}/K$) and mid- (WISE W1234) infrared properties. 97\% of the VH$z$Q sample is detected in one or more NIR…

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…

Obscuration in quasars may arise from steep viewing angles along the dusty torus, or instead may represent a distinct phase of supermassive black hole growth. We test these scenarios by probing the host dark matter halo environments of…

We present the first rest-frame UV population study of 17 heavily reddened, high-luminosity (E(B-V)$_{\rm{QSO}}\gtrsim$ 0.5; L$_{\rm{bol}}>$ 10$^{46}$ergs$^{-1}$) broad-line quasars at $1.5 < z < 2.7$. We combine the first year of deep,…

This is the second installment for the Large Sky Area Multi-Object Fibre Spectroscopic Telescope (LAMOST) Quasar Survey, which includes quasars observed from September 2013 to June 2015. There are 9024 confirmed quasars in DR2 and 10911 in…

We present the Lyman-$\alpha$ (Ly$\alpha$) and ultraviolet (UV) luminosity function (LF), in bins of redshift, of quasars selected in the Physics of the Accelerating Universe Survey (PAUS). A sample of 915 objects was selected at…

We determine the number counts and z=0-5 luminosity function for a well-defined, homogeneous sample of quasars from the Sloan Digital Sky Survey (SDSS). We conservatively define the most uniform statistical sample possible, consisting of…

We present results of a study of 12 dust-reddened quasars with 0.4 < z < 2.65 and reddenings in the range 0.15 < E(B-V) < 1.7. We obtained ACIS-S X-ray spectra of these quasars, estimated the column densities towards them, and hence…

We investigate the group-scale environment of 15 luminous quasars (luminosity $L_{\rm 3000}>10^{46}$ erg s$^{-1}$) from the Cosmic Ultraviolet Baryon Survey (CUBS) at redshift $z\approx1$. Using the Multi Unit Spectroscopic Explorer (MUSE)…

A crucial test of any cosmological model is the distribution of distant objects such as quasars. Because of well defined selection criteria quasars found by a ultraviolet excess (UVX) survey are ideal candidates for testing the model out to…

We present a well-designed sample of more than 1000 type 1 quasars at $3.5<z<5$ and derive UV quasar luminosity functions (QLFs) in this redshift range. These quasars were selected using the Sloan Digital Sky Survey (SDSS) imaging data in…

The Legacy Survey of Space and Time (LSST), being conducted by the Vera C. Rubin Observatory, is a wide-field multi-band survey that will revolutionize our understanding of extragalactic sources through its unprecedented combination of area…

We examine the clustering of quasars over a wide luminosity range, by utilizing 901 quasars at $\overline{z}_{\rm phot}\sim3.8$ with $-24.73<M_{\rm 1450}<-22.23$ photometrically selected from the Hyper Suprime-Cam Subaru Strategic Program…