An Empirical Ultraviolet Template for Iron Emission in Quasars as Derived from I Zw 1

Abstract

We present an empirical template spectrum suitable for fitting/subtracting and studying the FeII and FeIII line emission in the restframe UV spectra of active galatic nuclei (AGNs), the first empirical UV iron template to cover the full 1250 - 3090 A range. Iron emission is often a severe contaminant in optical--UV spectra of AGNs. Its presence complicates and limits the accuracy of measurements of both strong and weak emission lines and the continuum emission, affecting studies of line and continuum interrelations, the ionization structure, and elemental abundances in AGNs. Despite the wealth of work on modeling the AGN FeII emission and the need to account for it in observed AGN spectra, there is no UV template electronically available to aid this process. The iron template we present is based on HST spectra of the Narrow Line Seyfert 1, IZw1. Its intrinsic narrow lines (~900 km/s) and rich iron spectrum make the template particularly suitable for use with most AGN spectra. The iron emission spectrum and the line identifications and measurements are presented and compared with the work of Laor et al. We illustrate the application of the derived FeII and FeIII templates by fitting and subtracting the iron emission from UV spectra of four high-z quasars and of the nearby quasar, 3C273. We briefly discuss the small discrepancies between this observed iron emission and the UV template, and compare the template with previously published ones. We discuss the advantages and limitations of the templates and of the template fitting method. We conclude that the templates work sufficiently well to be a valuable and important tool for eliminating and studying the iron emission in AGNs, at least until accurate theoretical iron emission models are developed. (Abridged)

73 pages including 7 figures, 6 tables. To appear in ApJS. Preprint is also available at http://www.astronomy.ohio-state.edu/~vester/IronEmission/

Cited by in corpus (403)

• A Catalog of Quasar Properties from SDSS DR7
• Determining Central Black Hole Masses in Distant Active Galaxies and Quasars. II. Improved Optical and UV Scaling Relationships
• An ultra-luminous quasar with a twelve-billion-solar-mass black hole at redshift 6.30
• The cosmological evolution of quasar black-hole masses
• Biases in Virial Black Hole Masses: An SDSS Perspective
• A Luminous Quasar at Redshift 7.642
• Determining Central Black Hole Masses in Distant Active Galaxies
• The Discovery of the First "Changing Look" Quasar: New Insights into the Physics & Phenomenology of AGN
• A Catalog of Broad Absorption Line Quasars from the Sloan Digital Sky Survey Third Data Release
• Mass Functions of the Active Black Holes in Distant Quasars from the Large Bright Quasar Survey, the Bright Quasar Survey, and the Color-Selected Sample of the SDSS Fall Equatorial Stripe
• Unusual Broad Absorption Line Quasars from the Sloan Digital Sky Survey
• On the cosmic evolution of the scaling relations between black holes and their host galaxies: Broad Line AGN in the zCOSMOS survey
• Broad Emission Line Shifts in Quasars: An Orientation Measure for Radio-Quiet Quasars?
• Pōniuā'ena: A Luminous $z=7.5$ Quasar Hosting a 1.5 Billion Solar Mass Black Hole
• Physical properties of 15 quasars at $z\gtrsim 6.5$
• Space Telescope and Optical Reverberation Mapping Project. III. Optical Continuum Emission and Broad-Band Time Delays in NGC 5548
• The unusual emission line spectrum of IZw1
• Discovery of three z>6.5 quasars in the VISTA Kilo-degree Infrared Galaxy (VIKING) survey
• Comparing Single-Epoch Virial Black Hole Mass Estimators for Luminous Quasars
• Gemini Near-infrared Spectroscopy of Luminous z~6 Quasars: Chemical Abundances, Black Hole Masses, and MgII Absorption
• Black Hole Growth to z = 2 - I: Improved Virial Methods for Measuring M_BH and L/L_Edd
• Fe II Emission in 14 Low-Redshift Quasars: I - Observations
• Black hole masses and enrichment of z ~ 6 SDSS quasars
• Spectroscopy of Broad Line Blazars from 1LAC
• The Black Hole Mass - Galaxy Bulge Relationship for QSOs in the SDSS DR3
• The z=5 Quasar Luminosity Function from SDSS Stripe 82
• Estimating Black Hole Masses in Active Galactic Nuclei Using the MgII 2800 Emission Line
• Spectral properties of quasars from Sloan Digital Sky Survey data release 14: The catalog
• Evidence for non-evolving FeII/MgII ratios in rapidly accreting z~6 QSOs
• A statistical relation between the X-ray spectral index and Eddington ratio of active galactic nuclei in deep surveys
• Black hole mass estimates and emission-line properties of a sample of redshift z>6.5 quasars
• Analysis of optical Fe II emission in a sample of AGN spectra
• Early Growth and Efficient Accretion of Massive Black Holes at High Redshift
• The SDSS-III Baryon Oscillation Spectroscopic Survey: The Quasar Luminosity Function from Data Release Nine
• The Evolution of the Broad-Line Region among SDSS Quasars
• Gemini GNIRS near-infrared spectroscopy of 50 quasars at z>~5.7
• A Catalog of Quasar Properties from Sloan Digital Sky Survey Data Release 16
• The Sloan Digital Sky Survey Reverberation Mapping Project: Sample Characterization
• Continuum and Emission Line Strength Relations for a large Active Galactic Nuclei Sample
• A Significantly Neutral Intergalactic Medium Around the Luminous z=7 Quasar J0252-0503
• The Sloan Digital Sky Survey Reverberation Mapping Project: Velocity Shifts of Quasar Emission Lines
• Constraints on Black Hole Growth, Quasar Lifetimes, and Eddington Ratio Distributions from the SDSS Broad Line Quasar Black Hole Mass Function
• Black hole mass estimate for a sample of radio-loud narrow-line Seyfert 1 galaxies
• Exploring Reionization-Era Quasars III: Discovery of 16 Quasars at $6.4\lesssim z\lesssim 6.9$ with DESI Legacy Imaging Surveys and UKIRT Hemisphere Survey and Quasar Luminosity Function at $z\sim 6.7$
• Changing-Look Quasar Candidates: First Results from Follow-up Spectroscopy of Highly Optically Variable Quasars
• Discovery of the First Low-Luminosity Quasar at z > 7
• Iron Emission in the z=6.4 Quasar SDSS J114816.64+525150.3
• A Systematic Analysis of Fe II Emission in Quasars: Evidence for Inflow to the Central Black Hole
• Probing the Coevolution of Supermassive Black Holes and Quasar Host Galaxies
• Active galactic nuclei at z~1.5: II. Black Hole Mass estimation by means of broad emission lines
• The Origin of Fe II Emission in AGN
• Systematic Uncertainties in Black Hole Masses Determined from Single Epoch Spectra
• HST STIS Ultraviolet Spectral Evidence for Outflow in Extreme Narrow-line Seyfert 1 Galaxies: I. Data and Analysis
• Microlensing of the broad line region in 17 lensed quasars
• FeII/MgII Emission Line Ratio in High Redshift Quasars
• Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs). VI. Black Hole Mass Measurements of Six Quasars at 6.1<z<6.7
• The Discovery of A Luminous Broad Absorption Line Quasar at A Redshift of 7.02
• No significant evolution of relations between Black hole mass and Galaxy total stellar mass up to z~2.5
• Quasar Elemental Abundances at High Redshifts
• Mass Functions of the Active Black Holes in Distant Quasars from the Sloan Digital Sky Survey Data Release 3
• Outflows and the Physical Properties of Quasars
• The black hole - bulge mass relation of Active Galactic Nuclei in the Extended Chandra Deep Field - South Survey
• Lyα emission line reconstruction for high-$z$ QSOs
• Predicted FeII Emission-Line Strengths from Active Galactic Nuclei
• Black-Hole Mass and Growth Rate at z~4.8: A Short Episode of Fast Growth Followed by Short Duty Cycle Activity
• The Intrinsically X-ray Weak Quasar PHL 1811. II. Optical and UV Spectra and Analysis
• Iron Emission in z~6 QSOs
• Active Galactic Nuclei Emission-Line Properties Versus Eddington Ratio
• The cosmic growth of the active black hole population at 1<z<2 in zCOSMOS, VVDS and SDSS
• The X-shooter/ALMA Sample of Quasars in the Epoch of Reionization. II. Black Hole Masses, Eddington Ratios, and the Formation of the First Quasars
• Multi-wavelength study of the gravitational lens system RXS J1131-1231: III. Long slit spectroscopy: micro-lensing probes the QSO structure
• The X-SHOOTER/ALMA sample of Quasars in the Epoch of Reionization. I. NIR spectral modeling, iron enrichment and broad emission line properties
• Low-ionization Line Emission from Starburst Galaxies: A New Probe of Galactic-Scale Outflows
• Three new VHS-DES Quasars at 6.7 < z < 6.9 and Emission Line Properties at z > 6.5
• Broad Line Region Physical Conditions along the Quasar Eigenvector 1 Sequence
• Highly Accreting Quasars: Sample Definition and Possible Cosmological Implications
• Luminosity Function from dedicated SDSS-III and MMT data of quasars in 0.7<z<4.0 selected with a new approach
• The Central Engines of Fermi Blazars
• Supermassive Black Hole Binary Candidates from the Pan-STARRS1 Medium Deep Survey
• The Faint End of the z=5 Quasar Luminosity Function from the CFHTLS
• Detecting and Characterizing Young Quasars I: Systemic Redshifts and Proximity Zones Measurements
• Observational Constraints on the Dependence of Radio-Quiet Quasar X-ray Emission on Black Hole Mass and Accretion Rate
• Redshift Evolution in Black Hole-Bulge Relations: Testing CIV-based Black Hole Masses
• The correlations between optical variability and physical parameters of quasars in SDSS Stripe 82
• Implications of infalling Fe II - emitting clouds in active galactic nuclei: anisotropic properties
• Flare-like variability of the Mg IIλ2800Å emission line in the gamma-ray blazar 3C 454.3
• X-ray spectral properties of the AGN sample in the northern XMM-XXL field
• The discovery of a highly accreting, radio-loud quasar at z=6.82
• Spectral variability of quasars from multi-epoch photometric data in the Sloan Digital Sky Survey Stripe 82
• High Redshift Quasars and Star Formation in the Early Universe
• Evolution in the Black Hole - Galaxy Scaling Relations and the Duty Cycle of Nuclear Activity in Star-Forming Galaxies
• BLR Physical Conditions in Extreme Population A Quasars: a Method to Estimate Central Black Hole Mass at High Redshift
• Early star formation traced by the highest redshift quasars
• A survey of luminous high-redshift quasars with SDSS and WISE II. the bright end of the quasar luminosity function at z ~ 5
• Constraining Sub-Parsec Binary Supermassive Black Holes in Quasars with Multi-Epoch Spectroscopy. III. Candidates from Continued Radial Velocity Tests
• XQR-30: the ultimate XSHOOTER quasar sample at the reionization epoch
• Calibrating CIV-based black hole mass estimators
• What controls the Fe II strength in active galactic nuclei?
• The Civ line width distribution for quasars and its implications for broad-line region dynamics and virial mass estimation
• A Relation Between Supermassive Black Hole Mass and Quasar Metallicity?
• Occurrence and Global Properties of Narrow CIV lambda 1549 Absorption Lines in Moderate-Redshift Quasars
• Widespread, strong outflows in XQR-30 quasars at the Reionisation epoch
• Geometry and inclination of the broad line region in blazars
• QSFit: Automatic analysis of optical AGN spectra
• A probable Milli-Parsec Supermassive Binary Black Hole in the Nearest Quasar Mrk 231
• Spectral Properties From Lyman-alpha to H-alpha For An Essentially Complete Sample of Quasars I: Data
• The black hole fundamental plane from a uniform sample of radio and X-ray emitting broad line AGNs
• Low-z MgII Broad Absorption-Line Quasars from the Sloan Digital Sky Survey
• The Time Domain Spectroscopic Survey: Changing-Look Quasar Candidates from Multi-Epoch Spectroscopy in SDSS-IV
• Revealing the Accretion Physics of Supermassive Black Holes at Redshift z~7 with Chandra and Infrared Observations
• Detection of Rest-frame Optical Lines from X-shooter Spectroscopy of Weak Emission Line Quasars
• A Systematic Search for Periodically Varying Quasars in Pan-STARRS1: An Extended Baseline Test in Medium Deep Survey Field MD09
• Microlensing variability in the gravitationally lensed quasar Q2237+0305 = the Einstein Cross, I. Spectrophotometric monitoring with the VLT
• Constraints for the accretion disk evaporation rate in AGN from the existence of the Broad Line Region
• Evolution of the X-ray Emission of Radio-Quiet Quasars
• Quasar Accretion Disk Sizes from Continuum Reverberation Mapping in the DES Standard Star Fields
• First Spectroscopic Study of a Young Quasar
• Supermassive Black Hole Mass Estimates Using Sloan Digital Sky Survey Quasar Spectra at 0.7 < z < 2
• Accretion Disk Temperatures and Continuum Colors in QSOs
• Quasar Evolution and the Baldwin Effect in the Large Bright Quasar Survey
• The Sloan Digital Sky Survey Reverberation Mapping Project: Low-Ionization Broad-Line Widths and Implications for Virial Black Hole Mass Estimation
• Eddington ratio governs the equivalent width of MgII emission line in active galactic nuclei
• The correlations between optical/UV broad lines and X-ray emission for a large sample of quasars
• Simulations of the OzDES AGN Reverberation Mapping Project
• Constraints on the black hole spin in the quasar SDSS J094533.99+100950.1
• 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
• Performance of the Quasar Spectral Templates for the Dark Energy Spectroscopic Instrument
• Discovery Of Cold, Pristine Gas Possibly Accreting Onto An Overdensity Of Star-Forming Galaxies At Redshift z ~ 1.6
• The Sloan Digital Sky Survey Reverberation Mapping Project: How Broad Emission Line Widths Change When Luminosity Changes
• Estimate black hole masses of AGNs using ultraviolet emission line properties
• On the origin of excess cool gas in quasar host halos
• Stratified disc wind models for the AGN broad-line region: ultraviolet, optical and X-ray properties
• The structure of the Mg II broad line emitting region in Type 1 AGNs
• No Redshift Evolution in the Broad Line Region Metallicity up to z=7.54: Deep NIR Spectroscopy of ULAS J1342+0928
• Towards equation of state of dark energy from quasar monitoring: Reverberation strategy
• Low-Ionization Outflows in High Eddington Ratio Quasars
• Variability of Fe II Emission Features in the Seyfert 1 Galaxy NGC 5548
• Zooming into the broad line region of the gravitationally lensed quasar Q2237+0305 = the Einstein Cross: III. Determination of the size and structure of the CIV and CIII] emitting regions using microlensing
• High metal content of highly accreting quasars
• XQR-30: Black Hole Masses and Accretion Rates of 42 z>6 Quasars
• SDSS J094533.99+100950.1 - the remarkable weak emission line quasar
• EIGER III. JWST/NIRCam observations of the ultra-luminous high-redshift quasar J0100+2802
• Multiwavelength behaviour of the blazar 3C279: decade-long study from $\gamma$-ray to radio
• Virial Masses of Black Holes from Single Epoch Spectra of AGN
• Evidence for a Starburst within 9 pc of the Active Nucleus of NGC 1097
• The puzzling case of the radio-loud QSO 3C 186: a gravitational wave recoiling black hole in a young radio source?
• Black Hole Masses of Intermediate-Redshift Quasars: Near Infrared Spectroscopy
• Exploring Changing-look Active Galactic Nuclei with the Sloan Digital Sky Survey V: First Year Results
• Testing AGN outflow and accretion models with CIV and HeII emission line demographics in z=2 quasars
• Photometric Reverberation Mapping of the Broad Emission Line Region in Quasars
• The Changing-Look Quasar Mrk 590 is Awakening
• A quasar reddened by a sub-parsec sized, metal-rich and dusty cloud in a damped Lyman-alpha absorber at z=2.13
• Implications of Quasar Black Hole Masses at High Redshifts
• Extending the Calibration of CIV-Based Single-Epoch Black Hole Mass Estimators for Active Galactic Nuclei
• Evidence for variability timescale dependent UV/X-ray delay in Seyfert 1 AGN NGC 7469
• The Composite Spectrum of BOSS Quasars Selected for Studies of the Lyman-alpha Forest
• How does the Polar Dust affect the Correlation between Dust Covering Factor and Eddington Ratio in Type 1 Quasars Selected from the Sloan Digital Sky Survey Data Release 16?
• Ultraviolet and optical properties of Narrow-Line Seyfert 1 galaxies
• A Sample of Quasars with Strong Nitrogen Emission Lines from the Sloan Digital Sky Survey
• Improved Fe II emission line models for AGN using new atomic datasets
• Statistical Properties of Multi-epoch Spectral Variability of SDSS Stripe82 Quasars
• The Properties of Post-Starburst Quasars Based on Optical Spectroscopy
• Time-delay measurement of MgII broad line response for the highly-accreting quasar HE 0413-4031: Implications for the MgII-based radius-luminosity relation
• Probing the Nature of High Redshift Weak Emission Line Quasars: A Young Quasar with a Starburst Host Galaxy
• IZw1 observed with XMM-Newton: Low-energy spectral complexity, iron lines, and hard X-ray flares
• Calibration and Limitations of the Mg II line-based Black Hole Masses
• Swift/UVOT grism monitoring of NGC 5548 in 2013: an attempt at MgII reverberation mapping
• The Shocking Power Sources of LINERs
• The quasar M_bh - M_host relation through Cosmic Time I - Dataset and black hole masses
• The orientation dependence of quasar single-epoch black hole mass scaling relationships
• Simultaneous Ultraviolet and Optical Emission-line Profiles of Quasars: Implications for Black Hole Mass Determination
• The CaFe Project: Optical Fe II and Near-Infrared Ca II triplet emission in active galaxies -- simulated EWs, the co-dependence of cloud sizes and metal content
• Eddington ratio Distribution of X-ray selected broad-line AGNs at 1.0<z<2.2
• The emission spectrum of the strong Fe II emitter BAL Seyfert 1 galaxy IRAS 07598+6508
• Moderate-Luminosity Growing Black Holes From 1.25 < z < 2.7: Varied Accretion In Disk-Dominated Hosts
• GTC Spectra of z ~ 2.3 Quasars: Comparison with Local Luminosity Analogues
• An ultra-luminous quasar at z=5.363 with a ten billion solar mass black hole and a Metal-Rich DLA at z~5
• Probing the Origins of the CIV and Fe Kalpha Baldwin Effect
• The evolution of host mass and black hole mass in QSOs from the 2dF QSO Redshift Survey
• The extent of the MgII absorbing circum-galactic medium of quasars
• CLOUDY view of the warm corona
• Dynamically evolving Mg II broad absorption line flow in SDSS J133356.02+001229.1
• Flat-Spectrum Radio Quasars from SDSS DR3 Quasar Catalogue
• The Pan-STARRS1 $\mathbf{z}>5.6$ Quasar Survey: III. The $\mathbf{z}\approx 6$ Quasar Luminosity Function
• The Sloan Digital Sky Survey Reverberation Mapping Project: the CIV Blueshift, Its Variability, and Its Dependence Upon Quasar Properties
• Reverberation mapping of narrow-line Seyfert 1 galaxy I Zwicky 1: black hole mass
• Metallicity in Quasar Broad Line Regions at Redshift $\sim$ 6
• OzDES Reverberation Mapping Program: The first Mg II lags from five years of monitoring
• A New Iron Emission Template for Active Galactic Nuclei. I. Optical Template for the H$\beta$ region
• On the cool gaseous haloes of quasars
• The Large Sky Area Multi-object Fiber Spectroscopic Telescope (LAMOST) Quasar Survey: Quasar Properties from Data Release Six to Nine
• Super-Eddington Accretion in the WISE-Selected Extremely Luminous Infrared Galaxy W2246-0526
• The mass of the black hole in RE J1034+396
• VLT+UVES Spectroscopy of the CaII LoBAL Quasar SDSS J030000.56+004828.0
• Optical and radio properties of giant radio quasars: Central black hole characteristics
• The Black Hole Mass - Stellar Velocity Dispersion Relationship for Quasars in the Sloan Digital Sky Survey Data Release 7
• Extreme quasars at high redshift
• Rapid Black Hole Growth at the Dawn of the Universe: A Super-Eddington Quasar at z=6.6
• Lens-Aided Multi-Angle Spectroscopy (LAMAS) Reveals Small-Scale Outflow Structure in Quasars
• A comparative analysis of virial black-hole mass estimates of moderate-luminosity active galactic nuclei using Subaru/FMOS
• Eddington ratios of faint AGN at intermediate redshift: Evidence for a population of half-starved black holes
• Spectral Variability of Quasars in the Sloan Digital Sky Survey. II: The C IV Line
• The FeII/MgII flux ratio of low-luminosity quasars at z~3
• Probing the Origin of Changing-look Quasar Transitions with Chandra
• Microlensing and Intrinsic Variability of the Broad Emission Lines of Lensed Quasars
• The Physical Properties of Low Redshift FeLoBAL Quasars. I. Spectral Synthesis Analysis of the BAL Outflows using $SimBAL$
• The WISSH Quasars Project IV. BLR versus kpc-scale winds
• Theoretical FeI/II/III Emission-Line Strengths from Active Galactic Nuclei with Broad-Line Regions
• The Optical and Ultraviolet Emission-Line Properties of Bright Quasars with Detailed Spectral Energy Distributions
• Chemical Abundance of z~6 Quasar Broad-Line Regions in the XQR-30 Sample
• A Herschel Study of 24 micron-Selected AGNs and Their Host Galaxies
• Exploring the link between C IV outflow kinematics and sublimation-temperature dust in quasars
• Elemental Abundances in the Broad Emission Line Region of Quasars at Redshifts larger than 4
• Chemical evolution of the Universe at 0.7 < z < 1.6 derived from abundance diagnostics of the broad-line region of quasars
• SDSS-IV/SPIDERS: A Catalogue of X-Ray Selected AGN Properties; Spectral Properties and Black Hole Mass Estimates for SPIDERS SDSS DR14 Type 1 AGN
• A Metal-Strong and Dust-Rich Damped \lya Absorption System toward the Quasar SDSS J115705.52+615521.7
• The extended High A(V) Quasar Survey: Searching for dusty absorbers toward mid-infrared selected quasars
• Flare-like Variability of the Mg~II $\lambda$2798 Å Emission Line and UV Fe~II band in the Blazar CTA~102
• Unusual high-redshift radio BAL quasar 1624+3758
• What controls the UV-to-X-ray continuum shape in quasars?
• Fe II Diagnostic Tools for Quasars
• A Quasar Catalog with Simultaneous UV, Optical and X-ray Observations by Swift
• Spectral Variability of a Sample of Extreme Variability Quasars and Implications for the MgII Broad-line Region
• Multiwavelength Photometric and Spectropolarimetric Analysis of the FSRQ 3C 279
• Recurrence of the blue wing enhancements in the high ionization lines of SDSS 1004+4112 A
• The optical-UV emissivity of quasars: dependence on black hole mass and radio loudness
• A longer XMM-Newton look at I Zwicky 1: Variability of the X-ray continuum, absorption, and iron Kalpha line
• A longer XMM-Newton look at I Zwicky 1: physical conditions and variability of the ionised absorbers
• Ultraviolet Emission-Line Correlations in Hubble/COS Spectra of Active Galactic Nuclei: Single-Epoch Black Hole Masses
• Scatter Analysis Along the Multidimensional Radius-Luminosity Relations for Reverberation-Mapped Mg II Sources
• Microlensing of the broad emission lines in 27 gravitationally lensed quasars. Broad line region structure and kinematics
• The CaFe Project: Optical Fe II and Near-Infrared Ca II triplet emission in active galaxies: (I) Photoionization modelling
• Constraining the quasar population with the broad-line width distribution
• Quasars with Super Metal Rich Emission Line Regions
• Implications from the optical to UV flux ratio of FeII emission in quasars
• Constraining FeLoBAL outflows from absorption line variability
• Fe II emission in active galactic nuclei
• Panchromatic Properties of the Extreme FeII Emitter PHL 1092
• Near Infrared spectroscopic observations of high redshift C~{\sc i} absorbers
• Fundamental differences in the properties of red and blue quasars: measuring the reddening and accretion properties with X-shooter
• Characterizing Quasar CIV Emission-line Measurements from Time-resolved Spectroscopy
• The optical spectrum of PKS 1222+216 and its black hole mass
• Calibrating Mg II-based black-hole mass estimators using Low-to-High-Luminosity Active Galactic Nuclei
• Atomic data and spectral model for Fe III
• Fe III emission in quasars: evidence for a dense turbulent medium
• Placing High-Redshift Quasars in Perspective: a Catalog of Spectroscopic Properties from the Gemini Near Infrared Spectrograph -- Distant Quasar Survey
• Gravitational lens system SDSS J1339+1310: microlensing factory and time delay
• The spectral and environment properties of $z\sim 2.0-2.5$ quasar pairs
• Caught in the Act: Discovery of a Physical Quasar Triplet
• Systematic Redshift of the Fe III UV Lines in Quasars. Measuring Supermassive Black Hole Masses under the Gravitational Redshift Hypothesis
• Reaching the Peak of the quasar spectral energy distribution - II. Exploring the accretion disc, dusty torus and host galaxy
• Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs). XI. Proximity Zone Analysis for Faint Quasar Spectra at z~6
• Dating individual quasars with the HeII proximity effect
• A Near-Infrared Template Derived from I Zw 1 for the FeII Emission in Active Galaxies
• Extreme Variability Quasars in Their Various States. I: The sample selection and composite SDSS spectra
• Finding Quasars behind the Galactic Plane. II. Spectroscopic Identifications of 204 Quasars at $|b|<20°$
• Chandra and Magellan/FIRE follow-up observations of PSO167-13: an X-ray weak QSO at $z=6.515$
• Unshifted Metastable He I* Mini-Broad Absorption Line System in the Narrow Line Type 1 Quasar SDSS J080248.18$+$551328.9
• Microlensing of Quasar UV Iron Emission
• Potential signature of Population III pair-instability supernova ejecta in the BLR gas of the most distant quasar at z = 7.54
• A new method to obtain the Broad Line Region size of high redshift quasars
• The Extremely Luminous Quasar Survey (ELQS) in the Sloan Digital Sky Survey footprint. II. The North Galactic Cap Sample
• The optical variability of SDSS quasars from multi-epoch spectroscopy: I. Results from 60 quasars with $\ge$ six-epoch spectra
• Microlensing Constraints on Broad Absorption and Emission Line Flows in the Quasar H1413+117
• The accretion of a solar mass per day by a 17-billion solar mass black hole
• The variability of optical \feii emission in PG QSO 1700+518
• M_BH - sigma relation in SDSS flat-spectrum radio quasars
• Discovery and origins of giant optical nebulae surrounding quasar PKS 0454-22
• Quasar emission lines as probes of orientation: implications for disc wind geometries and unification
• Measurement of The Broad Line Region Size in a Luminous MACHO Quasar
• Discovery of late-time X-ray flare and anomalous emission line enhancement after the nuclear optical outburst in a narrow-line Seyfert 1 Galaxy
• A Thirty-Four Billion Solar Mass Black Hole in SMSS J2157-3602, the Most Luminous Known Quasar
• The Extreme Red Excess in Blazar Ultraviolet Broad Emission Lines
• High-redshift quasars along the Main Sequence
• SALT long-slit spectroscopy of LBQS 2113-4538: variability of the Mg II and Fe II component
• Streamlined Lensed Quasar Identification in Multiband Images via Ensemble Networks
• Electron-impact excitation of Fe${}^{2+}$: a comparison of intermediate coupling frame transformation, Breit-Pauli and Dirac R-matrix calculations
• Long-term optical spectroscopic variations in blazar 3C 454.3
• Probing Outflows in z= 1~2 Galaxies through FeII/FeII* Multiplets
• Relation between the variations in the MgII $\lambda 2798$ emission-line and the 3000 Å continuum
• Black Hole - Bulge Relationship of Post-Starburst Quasars at z \sim 0.3
• A very bright i=16.44 quasar in the `redshift desert' discovered by LAMOST
• Fantastic Fits with fantasy of Active Galactic Nuclei Spectra -- Exploring the Fe II emission near the H$\alpha$ line
• SALT long-slit spectroscopy of CTS C30.10: two-component Mg II line
• Chemical abundances along the quasar main sequence
• JWST ERS Program Q3D: The pitfalls of virial BH mass constraints shown in a z = 3 quasar with an ultramassive host
• The intermediate-ionization lines as virial broadening estimators for Population A quasars
• Simultaneous detection and analysis of optical and ultraviolet broad emission lines in quasars at z~2.2
• The rest-frame ultraviolet properties of radio-loud broad absorption line quasars
• Rapidly varying Mg II broad absorption line in SDSS J133356.02+001229.1
• Discovery of Balmer Broad Absorption Lines in the Quasar LBQS 1206+1052
• The properties of active galaxies at the extreme of eigenvector 1
• Behaviour of the MgII 2798AA Line Over the Full Range of AGN Variability
• Measuring Supermassive Black Hole Masses: Correlation between the Redshifts of the Fe III UV Lines and the Widths of Broad Emission Lines
• The rest-frame UV-to-optical spectroscopy of APM 08279+5255 - BAL classification and black hole mass estimates
• The Most Massive Active Galactic Nuclei at $1\lesssim z\lesssim 2$
• Mid-Infrared Selected Quasars I: Virial Black Hole Mass and Eddington Ratios
• The black hole - host galaxy relation for very low-mass quasars
• Multiwavelength analysis and the difference in the behavior of the spectral features during the 2010 and 2014 flaring periods of the blazar 3C 454.3
• A catalog of quasar properties from the Baryon Oscillation Spectroscopic Survey
• The warm outer layer of a Little Red Dot as the source of [Fe II] and collisional Balmer lines with scattering wings
• Baldwin Effect and Additional BLR Component in AGN with Superluminal Jets
• UV spectral diagnostics for low redshift quasars: estimating physical conditions and radius of the Broad Line Region
• Down-the-barrel observations of a multiphase quasar outflow at high redshift: VLT/X-shooter spectroscopy of the proximate molecular absorber at z=2.631 towards SDSS J001514+184212
• Seven broad absorption line quasars with excess broad band absorption near 2250 Å
• Quasar main sequence in the UV plane
• Black hole masses of weak emission line quasars based on continuum fit method
• The Infrared Medium-deep Survey. III. Survey of Luminous Quasars at 4.7 $\le$ z $\le$ 5.4
• Wavelength-resolved reverberation mapping of intermediate redshift quasars HE 0413-4031 and HE 0435-4312: Dissecting Mg II, optical Fe II, and UV Fe II emission regions
• A Candidate Dual QSO at Cosmic Noon
• Comparison of The UV and Optical Fe II Emission in Type 1 AGNs
• Black hole mass and spin estimates of the most distant quasars
• A Little Red Dot at $\mathbf{z}=7.3$ within a Large Galaxy Overdensity
• Fe II and Mg II in Luminous, Intermediate-Redshift Narrow-line Seyfert 1 Galaxies from the Sloan Digital Sky Survey
• Probing black hole accretion in quasar pairs at high redshift
• The eROSITA Final Equatorial Depth Survey (eFEDS): the hard X-ray selected sample
• A powerful (and likely young) radio-loud quasar at z=5.3
• High-redshift Narrow-line Seyfert 1 Galaxies: A Candidate Sample
• Discovery of the Most-Distant Double-Peaked Emitter at z=1.369
• Estimating black hole masses: Accretion disk fitting versus reverberation mapping and single epoch
• Hubble Space Telescope Ultraviolet Spectroscopy of Fourteen Low-Redshift Quasars
• Emission Line Variability during a Nonthermal Outburst in the Gamma-Ray Bright Quasar 1156+295
• Wavelength Dependences of the Optical/UV and X-ray Luminosity Correlations of Quasars
• Statistical analysis of AlIII 1860 and CIII] 1909 emission lines as virial black hole mass estimators in quasars
• Discovery of a Low-Redshift Hot Dust-Obscured Galaxy
• Radio-Loud and Radio-Quiet BAL Quasars: A Detailed Ultraviolet Comparison
• Ultraviolet emission lines of Si II in quasars --- investigating the "Si II disaster"
• Discovery of the most luminous quasar of the last 9 Gyr
• An X-ray fading, UV brightening QSO at $z\approx 6$
• The quasar SDSS J142507.32+323137.4 : dual AGNs?
• UV Fe II emission model of HE 0413-4031 and its relation to broad-line time delays
• JADES -- The small blue bump in GN-z11: insights into the nuclear region of a galaxy at z=10.6
• Optical IFU Observations of GOALS Sample with KOOLS-IFU on Seimei Telescope: Initial results of 9 U/LIRGs at $z<$ 0.04
• The U.S. Naval Observatory VLBI Spectroscopic Catalog
• A QSO plus host system lensed into a 6" Einstein ring by a low redshift galaxy
• Gemini Near Infrared Spectrograph - Distant Quasar Survey: Prescriptions for Calibrating UV-Based Estimates of Supermassive Black Hole Masses in High-Redshift Quasars
• Testing Einstein's Equivalence Principle and its Cosmological Evolution from Quasar Gravitational Redshifts
• Far-Ultraviolet Spectroscopy Of Active Galactic Nuclei With AstroSat/UVIT
• The MURALES survey. VII. Optical spectral properties of the nuclei of 3C radio sources at 0.3<z<0.82
• Composite spectra of quasars with different UV spectral index
• The low-mass end of the Mbh/Mhost relation in quasars
• Characterising SMSS J2157--3602, the most luminous known quasar, with accretion disc models
• A new apparent quasar pair: Q2225-403A,B
• A γ-ray emitting NLS1 galaxy SDSS J095909.51+460014.3 identified by multiwavelength contemporaneous brightening
• The Active Galactic Nuclei in the Hobby-Eberly Telescope Dark Energy Experiment Survey (HETDEX) II. Luminosity Function
• A Closer Look at Two of the Most Luminous Quasars in the Universe
• Comprehensive view on a $z\sim 6.5$ radio-loud QSO: from the radio to the optical/NIR to the X-ray band
• Unveiling the quasar main sequence: illuminating the complexity of active galactic nuclei and their evolution
• SALT long-slit spectroscopy of HE 0435-4312: fast displacement in the Mg II emission line
• When Spectral Modeling Meets Convolutional Networks: A Method for Discovering Reionization-era Lensed Quasars in Multi-band Imaging Data
• Detection of Iron Emission in the z = 5.74 QSO SDSSp J104433.04-012502.2
• Revealing the structure of the lensed quasar Q 0957+561: III. SMBH mass via gravitational redshift
• Spectroscopic follow-up of double quasar candidates
• AGN mass estimates in large spectroscopic surveys: the effect of host galaxy light
• Monster radio jet (>66 kpc) observed in quasar at z$\sim$5
• Exploring the links between quasar winds and radio emission along the Main Sequence at high redshift
• Deep CFHT Y-band Imaging of VVDS-F22 Field: II. Quasar Selection and Quasar Luminosity Function
• X-ray and Multiwavelength Insights into the Inner Structure of High-Luminosity Disc-Like Emitters
• Unveiling the monster heart: unbeamed properties of blazar 4C 71.07
• Optical Spectroscopy of Dual Quasar Candidates from the Subaru HSC-SSP program
• Fading Light, Fierce Winds: JWST Snapshot of a Sub-Eddington Quasar at Cosmic Dawn
• Elucidating the Correlation of the Quasar \ion{Fe}{2}/\ion{Mg}{2} Ratio with Redshift
• The detections of inflowing gas from narrow absorption lines at the parsec scale
• Probing the He II re-Ionization ERa via Absorbing C IV Historical Yield (HIERACHY) I: A Strong Outflow from a z~4.7 Quasar
• Gaia-assisted discovery of a detached low-ionisation BAL quasar with very large ejection velocities
• A Catalog of Post-starburst Quasars from Sloan Digital Sky Survey Data Release 7
• Quasars' Optical Polarization and Balmer Edge Feature Revealed by Ultra-Violet, and Polarized Visible to Near Infrared Emissions
• Evidence of Increased UV FeII Emission in Quasars in Candidate Overdense Regions
• SDSS spectroscopy for blazars in the $Fermi$ LAT bright AGN sample
• Uncertainty Quantification of the Virial Black Hole Mass with Conformal Prediction
• Discovery of six high-redshift quasars with the Lijiang 2.4m telescope and the Multiple Mirror Telescope
• Serendipitous discovery of a projected pair of QSOs separated by 4.5 arcsec on the sky
• Discovering bright quasars at intermediate redshifts based on the optical/near-IR colors
• Ultraviolet Fe II Emission in Fainter Quasars: Luminosity Dependences, and the Influence of Environments
• Narrow [O III] emission lines as a potential proxy for the evolutionary stage of quasars
• Accelerating lensed quasar discovery and modeling with physics-informed variational autoencoders
• Multi-phase investigation of outflows in the circumgalactic and interstellar media of luminous quasars at z~5
• Robust AGN and host-galaxy decomposition in optical spectral fitting
• The Large Sky Area Multi-object Fiber Spectroscopic Telescope (LAMOST) Quasar Survey: Quasar Properties from Data Release 10 to 12
• Extreme Galaxy-scale Outflows Are Frequent among Luminous Early Quasars
• A broad-line quasar with unexplained extreme velocity offsets: post-shock outflow?
• Ultradense Gases beyond Dusty Torus in a Partially Obscured Quasar
• The broad band SEDs of four 'hypervariable' AGN
• The CaFe Project: Optical FeII and Near-Infrared Ca II triplet emission in active galaxies. II. The driver(s) of the Ca II and Fe II and its potential use as a chemical clock
• A simple non-parametric method for resolving merged doublet lines: Insights into complex kinematics and outflows
• Mg II line properties in lobe-dominated quasars
• QUEST (Quasar Unsupervised Encoder and Synthesis Tool): A machine learning framework to generate quasar spectra
• Far-UV Fe Emission as Proxy of Eddington Ratios
• The Sloan Digital Sky Survey Reverberation Mapping Project: UV-Optical Accretion Disk Measurements with Hubble Space Telescope
• A New Member of the Fast and Furious Family: A Relativistic and Time-Variable UV Outflow in a Luminous Quasar
• Strong X-ray Variability of I Zwicky 1: Obscuration from Clumpy Accretion-Disk Winds
• Cold Quasar Investigation: Comparing Star Formation Rates to Black Hole Growth
• An equal mass ratio supermassive binary black holes in Q J0158-4325 with periodic microlensing signature?
• Models of Optical Emission Lines To Investigate Narrow-Line Seyfert 1 Galaxies in Spectroscopic Databases
• Evidence for the connection between star formation rate and evolutionary phases of quasars
• Strong correlation between FeII/MgII ratio and Eddington ratio of type 1 Active galactic nuclei
• ELFO: A Python Package for Emission Line Fitting Optimization in Integral Field Spectroscopy Data
• Spectroscopic confirmation of dual and offset quasars from the Subaru HSC-SSP program
• Indicators of Black Hole Mass and Eddington Accretion Ratio from QSO X-ray and UV Spectra
• The Relationship Between Emission Line and Continuum Luminosity and the Baldwin Effect in Blazars. I. The Case of the Mg II λ2798 Å Emission Line
• The miniJPAS survey quasar selection I: Mock catalogues for classification
• Testing [O II] $\lambda 3727$ as a Star Formation Rate Tracer in Quasar Host Galaxies
• Quiescent Host Galaxies of Extended Quasars Revealed by Spectrophotometric Decomposition