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Related papers: Extremely Red Quasars from SDSS, BOSS and WISE: Cl…

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The unprecedented sensitivity of the James Webb Space Telescope (JWST) has uncovered a surprisingly abundant population of mildly obscured, low-luminosity active galactic nuclei (AGNs) in the epoch of reionization (EoR). However, the link…

We present the first sample of spectroscopically confirmed heavily reddened broad-line quasars selected using the new near infra-red VISTA Hemisphere Survey and WISE All-Sky Survey. Observations of four candidates with (J-K)>2.5 and K<=16.5…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Manda Banerji , Richard G. McMahon , Paul C. Hewett , Eduardo Gonzalez-Solares , Sergey E. Koposov

The Two Micron All-Sky Survey (2MASS) has provided a uniform photometric catalog to search for previously unknown red AGN and QSOs. We have extended the search to the southern equatorial sky by obtaining spectra for 1182 AGN candidates…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Frank Masci , Roc Cutri , Paul Francis , Brant Nelson , John Huchra , D. Heath Jones , Matthew Colless , Will Saunders

We have selected a complete sample of 80 flat-spectrum radio quasars (FSRQs) from the WMAP 7-yr catalog within the SDSS area, all with measured redshift, and have inspected their SEDs looking for evidence of an AGN torus emission. A SED…

Astrophysics of Galaxies · Physics 2015-06-23 Gianluca Castignani , Gianfranco De Zotti

We present photometric analysis and follow-up spectroscopy for a population of extremely red stellar objects extracted from the point-source catalogue of the INT Photometric H-Alpha Survey (IPHAS) of the northern galactic plane. The vast…

We describe further results of a program aimed to yield ~10^4 fully characterized optical identifications of ROSAT X-ray sources. Our program employs X-ray data from the ROSAT All-Sky Survey (RASS), and both optical imaging and…

We present quasi-simultaneous multi-colour optical/near-IR photometry for 157 radio selected quasars, forming an unbiassed sub-sample of the Parkes Flat-Spectrum Sample. Data are also presented for 12 optically selected QSOs, drawn from the…

Astrophysics · Physics 2015-06-24 Paul J. Francis , Matthew T. Whiting , Rachel L. Webster

Recent studies of luminous infrared-selected active galactic nuclei (AGN) suggest that the reddest, most obscured objects display a higher angular clustering amplitude, and thus reside in higher-mass dark matter halos. This is a direct…

Astrophysics of Galaxies · Physics 2015-06-19 M. A. DiPompeo , A. D. Myers , R. C. Hickox , J. E. Geach , K. N. Hainline

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…

A minority of the optically selected quasar population are red at optical wavelengths due to the presence of dust along the line-of-sight. A key focus of many red quasar studies is to understand their relationship with the overall quasar…

Astrophysics of Galaxies · Physics 2019-07-10 Lizelke Klindt , David M. Alexander , David J. Rosario , Elisabeta Lusso , Sotiria Fotopoulou

We present the results of deep near-infrared observations of 11 hard X-ray selected sources in the Hellas2XMM survey, with faint optical magnitude (R>24) and high X-ray-to-optical flux ratio. All but one of the sources have been detected in…

High redshift blazars are an important class of Active Galactic Nuclei (AGN) that can provide an independent estimate of the supermassive black-hole mass function in high redshift radio-loud AGN without the bias due to absorption along the…

Quasars are galaxies hosting accreting supermassive black holes; due to their brightness, they are unique probes of the early universe. To date, only few quasars have been reported at $z > 6.5$ ($<$800 Myr after the Big Bang). In this work,…

The Wide-field Infrared Survey Explorer (WISE) has scanned the entire sky with unprecedented sensitivity in four infrared bands, at 3.4, 4.6, 12, and 22 micron. The WISE Point Source Catalog contains more than 560 million objects, among…

Astrophysics of Galaxies · Physics 2015-06-18 Robert Nikutta , Maia Nenkova , Zeljko Ivezic , Nicholas Hunt-Walker , Moshe Elitzur

The Swift Burst Alert Telescope (BAT) is discovering interesting new objects while monitoring the sky in the 14-195 keV band. Here we present the X-ray properties and spectral energy distributions for two unusual AGN sources. Both NVSS…

High Energy Astrophysical Phenomena · Physics 2015-06-04 J. Drew Hogg , Lisa M. Winter , Richard Mushotzky , Christopher Reynolds , Margaret Trippe

The largest K-band flux-limited sample of luminous quasars to date has been constructed from the UKIDSS Large Area Survey Early Data Release, covering an effective area of 12.8 deg^2. Exploiting the K-band excess of all quasars with respect…

Astrophysics · Physics 2009-11-13 Natasha Maddox , Paul C. Hewett , S. J. Warren , S. M. Croom

We present near-IR, low resolution spectra of eight of the most distant quasars known, with redshifts in the range 4.9<z<6.4. Half of these quasars are characterized by deep, broad and blueshifted absorption features associated with both…

Astrophysics · Physics 2009-11-10 R. Maiolino , E. Oliva , F. Ghinassi , M. Pedani , F. Mannucci , R. Mujica , Y. Juarez

We observed 17 optically-selected, radio-quiet high-redshift quasars with the Chandra Observatory ACIS, and detected 16 of them. The quasars have redshift between 3.70 and 6.28 and include the highest redshift quasars known. When compared…

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 report the discovery of five quasars with redshifts of 4.67 - 5.27 and z'-band magnitudes of 19.5-20.7 M_B ~ -27. All were originally selected as distant quasar candidates in optical/near-infrared photometry from the Sloan Digital Sky…

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