Red and Reddened Quasars in the Sloan Digital Sky Survey

Abstract

We investigate the continuum and emission line properties of 4576 SDSS quasars as a function of their optical/UV SEDs. The optical/UV color distribution of our sample is roughly Gaussian, but with a red tail; we distinguish between 1) intrinsically blue (optically flat) quasars, 2) intrinsically red (optically steep) quasars, and 3) the 273 (6%) of our quasars whose continua are inconsistent with a single power-law and appear redder due to SMC-like dust reddening rather than synchrotron emission. The color distribution suggests that the population of moderately dust reddened broad-line quasars is smaller than that of unobscured quasars, but we estimate that a further 10% of the luminous quasar population is missing from the SDSS sample because of dust extinction with E(B-V)<0.5. We also investigate the emission and absorption line properties of these quasars as a function of color with regard to Boroson & Green type eigenvectors. Intrinsically red (optically steep) quasars tend to have narrower Balmer lines and weaker CIV, CIII], HeII and 3000A bump emission as compared with bluer (optically flatter) quasars. The change in strength of the 3000A bump appears to be dominated by the Balmer continuum and not by FeII emission. The dust reddened quasars have even narrower Balmer lines and weaker 3000A bumps, in addition to having considerably larger equivalent widths of [OII] and [OIII] emission. The fraction of broad absorption line quasars (BALQSOs) increases from ~3.4% for the bluest quasars to perhaps as large as 20% for the dust reddened quasars, but the intrinsic color distribution is affected by dust reddening. (abridged)

arXiv comment37 pages, 10 figures (3 color), 2 tables, accepted by AJ. For a version with higher quality figures, see ftp://astro.princeton.edu/gtr/redqsos/RichardsGT_redqsos.revised3.preprint.ps

References in corpus (42)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• The Sloan Digital Sky Survey: Technical Summary
• Composite Quasar Spectra From the Sloan Digital Sky Survey
• The Sloan Digital Sky Survey Photometric Camera
• The u'g'r'i'z' Standard Star Network
• Spectroscopic Target Selection in the Sloan Digital Sky Survey: The Quasar Sample
• Astrometric Calibration of the Sloan Digital Sky Survey
• A photometricity and extinction monitor at the Apache Point Observatory
• An Efficient Algorithm for Positioning Tiles in the Sloan Digital Sky Survey
• The 2dF QSO Redshift Survey - I. The Optical QSO Luminosity Function
• The Soft X-Ray Properties of a Complete Sample of Optically Selected Quasars II. Final Results
• Optical and Radio Properties of Extragalactic Sources Observed by the FIRST and SDSS Surveys
• A Modified Magnitude System that Produces Well-Behaved Magnitudes, Colors, and Errors Even for Low Signal-to-Noise Ratio Measurements
• Resolving the extragalactic hard X-ray background
• Determining Central Black Hole Masses in Distant Active Galaxies
• Unusual Broad Absorption Line Quasars from the Sloan Digital Sky Survey
• Broad Emission Line Shifts in Quasars: An Orientation Measure for Radio-Quiet Quasars?
• Properties of Radio-Selected Broad Absorption-Line Quasars from the FIRST Survey
• Simulation of Stellar Objects in SDSS Color Space
• A Classic Type 2 QSO
• Colors of 2625 Quasars at 0<z<5 Measured in the Sloan Digital Sky Survey Photometric System
• Composite Spectra from the FIRST Bright Quasar Survey
• The Sloan Digital Sky Survey Quasar Catalog I. Early Data Release
• Average Quasar Spectra in the Context of Eigenvector 1
• Non-LTE Models and Theoretical Spectra of Accretion Disks in Active Galactic Nuclei. III. Integrated Spectra for Hydrogen-Helium Disks
• A Catalog of Broad Absorption Line Quasars from the Sloan Digital Sky Survey Early Data Release
• The Reddest Quasars
• The correlation of line strength with luminosity and redshift from composite QSO spectra
• Quasars in the 2MASS Second Incremental Data Release
• X-ray properties of Red Active Galactic Nuclei
• Origin of the viewing-angle dependence of the optical continuum emission in quasars
• THE POLARIZED SPECTRUM OF THE FE II-RICH BAL QSO, IRAS 07598+6508
• The Optical/Near-IR Colours of Red Quasars
• An I-Band-Selected Sample of Radio-Emitting Quasars: Evidence for a Large Population of Red Quasars
• Clues to Quasar Broad Line Region Geometry and Kinematics
• Red synchrotron jets in Parkes quasars
• PMN J1632-0033: A new gravitationally lensed quasar
• Observations of Faint, Hard-Band X-ray Sources in the Field of CRSS J0030.5+2618 with the Chandra X-ray Observatory and the Hobby-Eberly Telescope
• [OII] Emission, Eigenvector 1 and Orientation in Radio-quiet Quasars
• The Redshift of a Lensing Galaxy in PMN J0134-0931
• Red Quasars and Quasar Evolution: the Case of BALQSO FIRST J155633.8+351758
• The Spectra of Red Quasars

Cited by in corpus (308)

• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• A Unified, Merger-Driven Model for the Origin of Starbursts, Quasars, the Cosmic X-Ray Background, Supermassive Black Holes and Galaxy Spheroids
• A Cosmological Framework for the Co-Evolution of Quasars, Supermassive Black Holes, and Elliptical Galaxies: I. Galaxy Mergers & Quasar Activity
• Spectral Energy Distributions and Multiwavelength Selection of Type 1 Quasars
• An Observational Determination of the Bolometric Quasar Luminosity Function
• The Sloan Digital Sky Survey Quasar Catalog V. Seventh Data Release
• The SDSS Quasar Survey: Quasar Luminosity Function from Data Release Three
• Obscured and unobscured active galactic nuclei in the Spitzer Space Telescope First Look Survey
• The SDSS View of the Palomar-Green Bright Quasar Survey
• The Subaru/XMM-Newton Deep Survey (SXDS). IV. Evolution of Lya Emitters from z=3.1 to 5.7 in the 1 deg^2 Field: Luminosity Functions and AGN
• The X-ray-to-Optical Properties of Optically-Selected Active Galaxies Over Wide Luminosity and Redshift Ranges
• Unification of Luminous Type 1 Quasars through CIV Emission
• Bolometric luminosities and Eddington ratios of X-ray selected Active Galactic Nuclei in the XMM-COSMOS survey
• The X-ray to optical-UV luminosity ratio of X-ray selected Type 1 AGN in XMM-COSMOS
• A Catalog of Broad Absorption Line Quasars from the Sloan Digital Sky Survey Third Data Release
• Candidate Type II Quasars from the Sloan Digital Sky Survey: I. Selection and Optical Properties of a Sample at 0.3<Z<0.83
• JADES. The diverse population of infant Black Holes at 4<z<11: merging, tiny, poor, but mighty
• Efficient Photometric Selection of Quasars from the Sloan Digital Sky Survey: II. ~1,000,000 Quasars from Data Release Six
• The Bolometric Quasar Luminosity Function at z = 0-7
• The incidence of obscuration in active galactic nuclei
• The Radiative Efficiency of Accretion Flows in Individual AGN
• On the Origin of [OII] Emission in Red Sequence and Post-starburst Galaxies
• The SDSS-III Baryon Oscillation Spectroscopic Survey: Quasar Target Selection for Data Release Nine
• Binary Quasars in the Sloan Digital Sky Survey: Evidence for Excess Clustering on Small Scales
• X-CIGALE: fitting AGN/galaxy SEDs from X-ray to infrared
• Comparing Single-Epoch Virial Black Hole Mass Estimators for Luminous Quasars
• A supernova origin for dust in a high-redshift quasar
• The Sloan Digital Sky Survey quasar catalog: ninth data release
• Continuum and Emission-Line Properties of Broad Absorption Line Quasars
• Evidence for Quasar Activity Triggered by Galaxy Mergers in HST Observations of Dust-reddened Quasars
• Dust Reddening in SDSS Quasars
• Four quasars above redshift 6 discovered by the Canada-France High-z Quasar Survey
• The luminosity dependence of the Type 1 AGN fraction
• What controls the C IV line profile in active galactic nuclei?
• Quasar Clustering from SDSS DR5: Dependences on Physical Properties
• Soft X-ray and Ultraviolet Emission Relations in Optically Selected AGN Samples
• Black hole masses and enrichment of z ~ 6 SDSS quasars
• Accretion states and radio loudness in Active Galactic Nuclei: analogies with X-ray binaries
• Spitzer's Contribution to the AGN Population
• The SDSS-III Baryon Oscillation Spectroscopic Survey: The Quasar Luminosity Function from Data Release Nine
• The WISSH Quasars Project I. Powerful ionised outflows in hyper-luminous quasars
• Chandra and Spitzer unveil heavily obscured quasars in the SWIRE/Chandra Survey
• Broad-line Balmer Decrements in Blue Active Galactic Nuclei
• Average Extinction Curves and Relative Abundances for QSO Absorption Line Systems at 1 <= z_abs < 2
• Fitting AGN/galaxy X-ray-to-radio SEDs with CIGALE and improvement of the code
• Photometric redshifts in the SWIRE Survey
• The Nuclear Reddening Curve for Active Galactic Nuclei and the Shape of the Infra-Red to X-Ray Spectral Energy Distribution
• FIRST-2MASS Red Quasars: Transitional Objects Emerging from the Dust
• Mean Spectral Energy Distributions and Bolometric Corrections for Luminous Quasars
• Accretion Rate and the Physical Nature of Unobscured Active Galaxies
• The FIRST-2MASS Red Quasar Survey II: An anomalously high fraction of LoBALs in searches for dust-reddened quasars
• Discovery of a Giant Lya Emitter Near the Reionization Epoch
• The FIRST-2MASS Red Quasar Survey
• Quasars and the Big Blue Bump
• The Origin of Dust in the Early Universe: Probing the Star Formation History of Galaxies by their Dust Content
• The Obscured Fraction of AGN in the XMM-COSMOS Survey: A Spectral Energy Distribution Perspective
• An X-shooter composite of bright 1 < z < 2 quasars from UV to infrared
• The VVDS type-1 AGN sample: The faint end of the luminosity function
• Evolution in the properties of Lyman-alpha emitters from redshifts z ~ 3 to z ~ 2
• Magnetohydrodynamic Simulations of Active Galactic Nucleus Disks and Jets
• The extinction law at high redshift and its implications
• Binary Quasars at High Redshift I: 24 New Quasar Pairs at z ~ 3-4
• Detailed Characterization of H_beta emission line profile in low z SDSS quasars
• Type 1 low z AGN. I. Emission properties
• SILVERRUSH. III. Deep Optical and Near-Infrared Spectroscopy for Lya and UV-Nebular Lines of Bright Lya Emitters at z=6-7
• [O II] Emission in Quasar Host Galaxies: Evidence for a Suppressed Star Formation Efficiency
• Candidate Type II Quasars from the SDSS: III. Spectropolarimetry Reveals Hidden Type I Nuclei
• Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs). VI. Black Hole Mass Measurements of Six Quasars at 6.1<z<6.7
• Outflows and the Physical Properties of Quasars
• Optical--to--X-ray emission in low-absorption AGN: Results from the Swift-BAT 9 month catalogue
• Lyα emission line reconstruction for high-$z$ QSOs
• Active galactic nuclei at z ~ 1.5: I. Spectral energy distribution and accretion discs
• Candidate Type II Quasars from the Sloan Digital Sky Survey: II. From Radio to X-Rays
• SDSS quasars in the WISE preliminary data release and quasar candidate selection with optical/infrared colors
• The UV Continuum of Quasars: Models and SDSS Spectral Slopes
• Extremely Red Quasars from SDSS, BOSS and WISE: Classification of Optical Spectra
• Galaxy counterparts of metal-rich damped Lyman-alpha absorbers - II. A solar-metallicity and dusty DLA at z_abs=2.58
• New Insights on the QSO Radio-Loud/Radio-Quiet Dichotomy: SDSS Spectra in the Context of the 4D Eigenvector1 Parameter Space
• Heavily reddened type 1 quasars at z > 2 I: Evidence for significant obscured black-hole growth at the highest quasar luminosities
• The Quasar Luminosity Function at Redshift 4 with Hyper Suprime-Cam Wide Survey
• Candidate Type II Quasars at 2 < z < 4.3 in the Sloan Digital Sky Survey III
• Heavily Reddened Quasars at z~2 in the UKIDSS Large Area Survey: A Transitional Phase in AGN Evolution
• Lensing, reddening and extinction effects of MgII absorbers from z=0.4 to z=2
• FIRST-2MASS Sources Below the APM Detection Threshold: A Population of Highly Reddened Quasars
• A population of high-redshift type-2 quasars-I. Selection Criteria and Optical Spectra
• Luminous K-band Selected Quasars from UKIDSS
• The Fifth Data Release Sloan Digital Sky Survey/XMM-Newton Quasar Survey
• Dust-reddening and gravitational lensing of SDSS QSOs due to foreground damped Lyman-alpha systems
• A dormant, overmassive black hole in the early Universe
• The X-ray Energy Dependence of the Relation between Optical and X-ray Emission in Quasars
• A dusty compact object bridging galaxies and quasars at cosmic dawn
• The Spitzer mid-infrared AGN survey. I - optical and near-infrared spectroscopy of candidate obscured and normal AGN selected in the mid-infrared
• Cold Accretion Disks and Lineless Quasars
• An Empirical Calibration of the Completeness of the SDSS Quasar Survey
• An Empirical Algorithm for Broad-band Photometric Redshifts of Quasars from the Sloan Digital Sky Survey
• ImpZ: a new photometric redshift code for galaxies and quasars
• Extinction due to amorphous carbon grains in red quasars from the SDSS
• Dust Attenuation in High Redshift Galaxies -- 'Diamonds in the Sky'
• On the HI content, dust-to-gas ratio and nature of MgII absorbers
• Double Lobed Radio Quasars from the Sloan Digital Sky Survey
• JADES -- The Rosetta Stone of JWST-discovered AGN: deciphering the intriguing nature of early AGN
• Fundamental differences in the radio properties of red and blue quasars: evolution strongly favoured over orientation
• Detections of the 2175 ÅDust Feature at 1.4z 1.5 from the Sloan Digital Sky Survey
• Polar Dust, Nuclear Obscuration and IR SED Diversity in Type-1 AGNs
• Metals and Dust in Intermediate-redshift Damped Ly-alpha Galaxies
• The Optical - Infrared Colors of CORALS QSOs: Searching for Dust Reddening Associated With High Redshift Damped Lyman Alpha Systems
• Mining for Dust in Type 1 Quasars
• The Chandra XBootes Survey - III: Optical and Near-IR Counterparts
• Eight-Dimensional Mid-Infrared/Optical Bayesian Quasar Selection
• The meaning of WISE colours - I. The Galaxy and its satellites
• Low-z MgII Broad Absorption-Line Quasars from the Sloan Digital Sky Survey
• Modelling type 1 quasar colours in the era of Rubin and Euclid
• Partially obscured quasars in the Sloan Digital Sky Survey Early Data Release
• Evidence for Photoionization Driven Broad Absorption Line Variability
• Spectroscopic Identification of Type 2 Quasars at Z < 1 in SDSS-III/BOSS
• Accretion Disk Temperatures and Continuum Colors in QSOs
• Eddington-Limited Accretion in z~2 WISE-selected Hot, Dust-Obscured Galaxies
• Extreme gas properties in the most distant quasars
• The average absorption properties of broad absorption line quasars at 800 < lambda_rest < 3000 Å, and the underlying physical parameters
• On the structure and energetics of quasar broad absorption-line outflows
• The radio loudness of SDSS quasars from the LOFAR Two-metre Sky Survey: ubiquitous jet activity and constraints on star formation
• The correlations between optical/UV broad lines and X-ray emission for a large sample of quasars
• Type 1 AGN at low z. III. The optical narrow line ratios
• Luminous WISE-selected Obscured, Unobscured, and Red Quasars in Stripe 82
• Constraints on the black hole spin in the quasar SDSS J094533.99+100950.1
• Optical Line Diagnostics of z~2 Optically Faint ULIRGs in the Spitzer Bootes Survey
• The large area KX quasar catalogue: I. Analysis of the photometric redshift selection and the complete quasar catalogue
• Connecting the X-ray properties of weak-line and typical quasars: testing for a geometrically thick accretion disk
• The sub-millimeter properties of broad absorption line quasars
• Black hole mass and Eddington ratio distribution functions of X-ray selected broad-line AGNs at z~1.4 in the Subaru XMM-Newton Deep Field
• Extinction and metal column density of HI regions up to redshift z~2
• ALMA Confirmation of an Obscured Hyperluminous Radio-Loud AGN at $z=6.853$ Associated with a Dusty Starburst in the 1.5 deg${}^2$ COSMOS Field
• A Study of Gravitational Lens Chromaticity using Ground-based Narrow Band Photometry
• Correlations of Quasar Optical Spectra with Radio Morphology
• Mean and Extreme Radio Properties of Quasars and the Origin of Radio Emission
• The multiwavelength properties of red QSOs -- Evidence for dusty winds as the origin of QSO reddening
• High redshift quasars and the supermassive black hole mass budget: constraints on quasar formation models
• The nature of damped Lyman alpha and sub-damped Lyman alpha absorbers
• SDSS J094533.99+100950.1 - the remarkable weak emission line quasar
• Unusual quasars from the Sloan Digital Sky Survey selected by means of Kohonen self-organising maps
• The Radio Properties of Type 2 Quasars
• The UV Properties of SDSS Selected Quasars
• The HELLAS2XMM survey. X. The bolometric output of luminous obscured quasars: The Spitzer perspective
• Evidence for a Starburst within 9 pc of the Active Nucleus of NGC 1097
• Fundamental differences in the radio properties of red and blue quasars: enhanced compact AGN emission in red quasars
• Evidence that most type 1 AGN are reddened by dust in the host ISM
• The Faint End of the Quasar Luminosity Function at z~4
• Dusty Tori of Luminous Type 1 Quasars at z \sim 2
• On the Scatter in the Radius - Luminosity Relationship for Active Galactic Nuclei
• Polar dust obscuration in broad-line active galaxies from the XMM-XXL field
• Extinction curve template for intrinsically reddened quasars
• Statistical Properties of Multi-epoch Spectral Variability of SDSS Stripe82 Quasars
• Exploring the dust content of SDSS DR7 damped Lyman alpha systems at 2.15$\le z_{ab}<$5.2
• The Properties of Post-Starburst Quasars Based on Optical Spectroscopy
• Hot-Dust-Poor Quasars in Mid-Infrared and Optically Selected Samples
• Are red 2MASS QSOs young?
• On the link between associated MgII absorbers and star formation in quasar hosts
• Average Properties of a Large Sample of z_abs ~ z_em associated Mg II Absorption Line Systems
• X-ray spectroscopic survey of highly-accreting AGN
• The picture of BLR in 2.5-D FRADO: Dynamics & Geometry
• The Sloan Digital Sky Survey Reverberation Mapping Project: Post-Starburst Signatures in Quasar Host Galaxies at z < 1
• Discovery of 24 radio-bright quasars at $4.9\le z\le 6.6$ using low-frequency radio observations
• A Transient "Changing-look'' Active Galactic Nucleus Resolved on Month Timescales from First-year Sloan Digital Sky Survey V Data
• Infrared emission of $z\sim 6$ galaxies: AGN imprints
• An Investigation into the Effects of Luminosity on the Mid-Infrared Spectral Energy Distributions of Radio-Quiet Quasars
• X-ray Observations of Luminous Dusty Quasars at z > 2
• Evolution of grain size distribution in high-redshift dusty quasars: Integrating large amounts of dust and unusual extinction curves
• Towards Detecting The 2175-Å Dust Feature Associated With Strong High Redshift Mg ßII Absorption Lines
• X-ray Insights Into Interpreting CIV Blueshifts and Optical/UV Continua
• Silicate Dust in Active Galactic Nuclei
• Fundamental differences in the radio properties of red and blue quasars: Insight from the LOFAR Two-metre Sky Survey (LoTSS)
• Anomalously Steep Reddening Law in Quasars: An Exceptional Example Observed in IRAS14026+4341
• Constraining the dynamical importance of hot gas and radiation pressure in quasar outflows using emission line ratios
• Astrometric Redshifts for Quasars
• Rapid Black Hole Growth at the Dawn of the Universe: A Super-Eddington Quasar at z=6.6
• The High A(V) Quasar Survey: Reddened quasi-stellar objects selected from optical/near-infrared photometry - II
• AGN spectral states from simultaneous UV and X-ray observations by XMM-Newton
• Two-Component Structure of the Hbeta Broad-Line Region in Quasars. I. Evidence from Spectral Principal Component Analysis
• CIV Emission and the Ultraviolet through X-ray Spectral Energy Distribution of Radio-Quiet Quasars
• Radio-Selected Quasars in the Sloan Digital Sky Survey
• A Herschel Study of 24 micron-Selected AGNs and Their Host Galaxies
• Quasar Photometric Redshifts and Candidate Selection: A New Algorithm Based on Optical and Mid-Infrared Photometric Data
• Sensitive Chandra coverage of a representative sample of weak-line quasars: revealing the full range of X-ray properties
• The [OIII] profiles of infrared-selected active galactic nuclei: More powerful outflows in the obscured population
• The Covering Factor of Warm Dust in Quasars: View from WISE All-Sky Data Release
• The WISE-2MASS Survey: Red Quasars Into the Radio Quiet Regime
• Investigation of dust attenuation and star formation activity in galaxies hosting GRBs
• Simulating Wide-Field Quasar Surveys from the Optical to Near-Infrared
• The Subaru-XMM-Newton Deep Survey (SXDS) VIII.: Multi-wavelength Identification, Optical/NIR Spectroscopic Properties, and Photometric Redshifts of X-ray Sources
• The extended High A(V) Quasar Survey: Searching for dusty absorbers toward mid-infrared selected quasars
• A Quasar Catalog with Simultaneous UV, Optical and X-ray Observations by Swift
• A Quasar-Galaxy Mixing Diagram: Quasar Spectral Energy Distribution Shapes in the Optical to Near-Infrared
• Searching for Dust Reddening in SDSS Spectra with Damped Lyman $\alpha${} Systems
• Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs) XII. Extended [C II] Structure (Merger or Outflow) in a z = 6.72 Red Quasar
• Ultra-luminous quasars at redshift $z>4.5$ from SkyMapper
• The Luminosity Function of bright QSOs at z~4 and implications for the cosmic ionizing background
• Fundamental differences in the properties of red and blue quasars: measuring the reddening and accretion properties with X-shooter
• Fundamental differences in the radio properties of red and blue quasars: kiloparsec-scale structures revealed by e-MERLIN
• A Dusty Mg~II absorber Associated with the Quasar SDSS J003545.13+011441.2
• Revealing HI gas in emission and absorption on pc to kpc scales in a galaxy at z ~ 0.017
• Color-redshift Relations and Photometric Redshift Estimations of Quasars in Large Sky Surveys
• Evidence for higher black hole spin in radio-loud quasars
• Discovery of H alpha absorption in the unusual broad absorption line quasar SDSS J083942.11+380526.3
• Do the spectral energy distributions of type 1 AGN show diversity?
• An extinction free AGN selection by 18-band SED fitting in mid-infrared in the AKARI NEP deep field
• Is GRB 050904 at z=6.3 absorbed by dust?
• Quasi-stellar objects in the ALHAMBRA survey. I. Photometric redshift accuracy based on a 23 optical-NIR filter photometry
• The Reddest DR3 SDSS/XMM Quasars
• Emission Line Spectroscopy of a Damped Lyman-alpha Absorbing Galaxy at z = 0.437
• On the Optical-to-Silicate Extinction Ratio as a Probe of the Dust Size in Active Galactic Nuclei
• Chandra Observations of Red Sloan Digital Sky Survey Quasars
• The Nature of LoBAL QSOs: I. SEDs and mid-infrared spectral properties
• Galaxies with Background QSOs, I: A Search for Strong Galactic H-alpha Lines
• The environment of weak emission-line quasars
• Dust in Active Galactic Nuclei: Anomalous Silicate to Optical Extinction Ratios?
• The evolution of dusty torus covering factor in quasars
• New Quasars Detected via Variability in the QUEST1 Survey
• The SDSS-XMM Quasar Sample: First Results
• Spectral Energy Distributions of Candidate Periodically-Variable Quasars: Testing the Binary Black Hole Hypothesis
• The Spectral Energy Distributions of Red 2MASS AGN
• Irradiation of accretion discs in active galactic nuclei due to warm absorber
• Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs). IX. Identification of Two Red Quasars at z > 5.6
• LBQS 0103-2753: A Binary Quasar in a Major Merger
• Beyond Simple AGN Unification with Chandra-observed 3CRR Sources
• Gemini-South + FLAMINGOS Demonstration Science: Near-Infrared Spectroscopy of the z=5.77 Quasar SDSS J083643.85+005453.3
• The dust attenuation law in $z\sim 6$ quasars
• Energy distribution of individual quasars from far-UV to X-rays: I. Intrinsic UV hardness and dust opacities
• Effect of extinction on quasar luminosity distances determined from UV and X-ray flux measurements
• Estimating reddening of the continuum and broad-line region of active galactic nuclei: the mean reddening of NGC 5548 and the size of the accretion disc
• Galactic nebular lines in the fiber spectra of background QSOs: Reaching a hundred QSO-galaxy pairs with spectroscopic and photometric measurements
• Searching for planetary-mass T-dwarfs in the core of Serpens
• A novel Bayesian approach for decomposing the radio emission of quasars: I. Modelling the radio excess in red quasars
• An Infrared Excess Identified in Radio-Loud Broad Absorption Line Quasars
• The Subaru/XMM-Newton Deep Field - II. The 37 brightest radio sources
• No evidence of "gray" dust from composite quasar spectra
• A systematic search for changing-look quasars in SDSS-II using difference spectra
• A Lyman-alpha-only AGN from the Sloan Digital Sky Survey
• Evolution of cold gas at 2<z<5: a blind search for HI and OH absorption lines towards mid-infrared color selected radio-loud AGNs
• Mid-Infrared Selected Quasars I: Virial Black Hole Mass and Eddington Ratios
• Quasars as a tracer of large-scale structures in the distant universe
• The Most Massive Active Galactic Nuclei at $1\lesssim z\lesssim 2$
• The rest-frame UV-to-optical spectroscopy of APM 08279+5255 - BAL classification and black hole mass estimates
• An Active Galactic Nucleus Recognition Model based on Deep Neural Network
• A Mote in Andromeda's Disk: a Misidentified Periodic AGN Behind M31
• A Big Red Dot: Scattered light, host galaxy signatures and multi-phase gas flows in a luminous, heavily reddened quasar at cosmic noon
• Estimators of Bolometric Luminosity and Black Hole Mass with Mid-infrared Continuum Luminosities for Dust-obscured Quasars: Prevalence of Dust-obscured SDSS Quasars
• A young, dusty, compact radio source within a Ly|*alpha*| halo
• Is the star formation rate in $z\sim 6$ quasars overestimated?
• Dust and gas obscuration in ELAIS Deep X-ray Survey reddened quasars
• The orientation and polarization of broad absorption line quasars
• Broad-band spectral energy distribution of 3000 Angstroem break quasars from the Sloan Digital Sky Survey
• Strong CaII absorption lines in the reddened quasar SDSS J2339$-$0912: Evidence of the collision/merger in the host galaxy?
• Infrared Imaging of SDSS Quasars: Implications for the Quasar K correction
• The Millennium Galaxy Catalogue: a census of local compact galaxies
• Host Dark Matter Halos of SDSS Red and Blue Quasars: No Significant Difference in Large-scale Environment
• Extended multiwavelength fuzz around red quasars: observational appearance of radiative feedback in action
• A Candidate Dual QSO at Cosmic Noon
• Far-infrared emission in luminous quasars accompanied by nuclear outflows
• A multi-wavelength survey of AGN in the XMM-LSS field: I. Quasar selection via the KX technique
• Investigating the nuclear properties of highly accreting active galactic nuclei with XMM-Newton
• Determining the fraction of reddened quasars in COSMOS with multiple selection techniques from X-ray to radio wavelengths
• How does the radio enhancement of broad absorption line quasars relate to colour and accretion rate?
• Spectroscopic classification of a complete sample of astrometrically-selected quasar candidates using Gaia DR2
• Characterizing Quasars in the Mid-infrared: High Signal-to-Noise Spectral Templates
• Are the Formation and Abundances of Metal-Poor Stars the Result of Dust Dynamics?
• Determining the Locations of Dust Sources in FeLoBAL Quasars
• The nature of sub-millimetre galaxies I: A comparison of AGN and star-forming galaxy SED fits
• An Exploratory Search for z~6 Quasars in the UKIDSS Early Data Release
• XMM-Newton spectra of hard spectrum Rosat AGN: X-ray absorption and optical reddening
• VPMS J1342+2840 - an unusual quasar from the variability and proper motion survey
• The Nature of Luminous Quasars with Very Large C IV Equivalent Widths
• Characterising SMSS J2157--3602, the most luminous known quasar, with accretion disc models
• Far-Ultraviolet Spectroscopy Of Active Galactic Nuclei With AstroSat/UVIT
• The Southern 2MASS AGN Survey: spectroscopic follow-up with 6dF
• Extinction law in ultraluminous infrared galaxies at z ~ 1
• Using a complete spectroscopic survey to find red quasars and test the KX method
• HYPERION: broad-band X-ray-to-near-infrared emission of Quasars in the first billion years of the Universe
• How are Red and Blue Quasars Different? The Radio Properties
• Improved selection of extremely red quasars with boxy CIV lines in BOSS
• Optical Spectroscopy of Dual Quasar Candidates from the Subaru HSC-SSP program
• The unusual UV continuum of quasar Ton 34 and the possibility of crystalline dust absorption
• Dust in the Local Group
• Modelling Grain Rotational Disruption by Radiative Torques and Extinction of Active Galactic Nuclei
• Properties of spectrally-defined red QSOs at z = 0.3-1.2
• Revealing the Warm and Hot Halo Baryons via Thomson Scattering of Quasar Light
• Probing the Wind Component of Radio Emission in Luminous High-Redshift Quasars
• A Catalog of Post-starburst Quasars from Sloan Digital Sky Survey Data Release 7
• The 2175 Å~ Bump Features in FeLoBAL Quasars: One Indicator of MW-like Dust in the Nuclear Region of Quasar
• Evidence for radio loud to radio quiet evolution from red and blue quasars
• The reddest ISO-2MASS quasar
• Revisiting the X-ray-to-UV relation of Quasars in the era of all-sky surveys
• PEARLS: Discovery of Point-Source Features Within Galaxies in the North Ecliptic Pole Time Domain Field
• A simple model of dust extinction in gamma-ray burst host galaxies
• Spectroscopic Quasar Anomaly Detection (SQuAD) I: Rest-Frame UV Spectra from SDSS DR16
• Nanodiamond dust and the energy distribution of quasars
• Deep absorption in SDSS J110511.15+530806.5
• Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs). XIV. A Candidate Type-II Quasar at z=6.1292
• DESI Mg II Absorbers: Extinction Characteristics & Quasar Redshift Accuracy
• Supernovae Light Curves: An Argument for a New Distance Modulus
• Aplicando modelos de granos de polvo con propiedades meteoriticas al continuo ionizante de algunos Nucleos Activos de Galaxias
• Evidence for the connection between star formation rate and evolutionary phases of quasars
• A quasar shedding its dust cocoon at redshift 2
• The Compact Star-Forming Galaxies at $2<z<3$ in 3D-HST/CANDELS: AGN and Non-AGN Physical Properties
• There Are (super)Giants in the Sky: Searching for Misidentified Massive Stars in Algorithmically-Selected Quasar Catalogs
• Constraining the AGN tori at cosmic noon using high-resolution JWST imaging and simultaneous SED fitting
• Near infrared imaging of the broad absorption line quasar BAL QSO 0134+3253
• Revealing a strongly reddened, faint active galactic nucleus population by stacking deep co-added images
• Giant radio quasars: composite optical spectra