Characterizing Quasar CIV Emission-line Measurements from Time-resolved Spectroscopy

Abstract

We use multi-epoch quasar spectroscopy to determine how accurately single-epoch spectroscopy can locate quasars in emission-line parameter space in order to inform investigations where time-resolved spectroscopy is not available. We explore the improvements in emission-line characterization that result from using non-parametric information from many lines as opposed to a small number of parameters for a single line, utilizing reconstructions based on an independent component analysis applied to the data from the Sloan Digital Sky Survey Reverberation Mapping project. We find that most of the quasars are well described by just two components, while more components signal a quasar likely to yield a successful reverberation mapping analysis. In single-epoch spectroscopy the apparent variability of equivalent width is exaggerated because it is dependent on the continuum. Multi-epoch spectroscopy reveals that single-epoch results do not significantly change where quasars are located in CIV parameter space and do not have a significant impact on investigations of the global Baldwin Effect. Quasars with emission line properties indicative of higher $L/L_{Edd}$ are less variable, consistent with models with enhanced accretion disk density. Narrow absorption features at the systemic redshift may be indicative of orientation (including radio-quiet quasars) and may appear in as much as 20% of the quasar sample. Future work applying these techniques to lower luminosity quasars will be important for understanding the nature of accretion disk winds.

arXiv commentSubmitted to ApJ June 19, 2020, Accepted July 13, 2020

References in corpus (59)

• The Sloan Digital Sky Survey: Technical Summary
• SDSS-III: Massive Spectroscopic Surveys of the Distant Universe, the Milky Way Galaxy, and Extra-Solar Planetary Systems
• The Baryon Oscillation Spectroscopic Survey of SDSS-III
• Determining Central Black Hole Masses in Distant Active Galaxies and Quasars. II. Improved Optical and UV Scaling Relationships
• Dynamics of line-driven disk winds in Active Galactic Nuclei
• Linear Regression for Astronomical Data with Measurement Errors and Intrinsic Scatter
• An Empirical Ultraviolet Template for Iron Emission in Quasars as Derived from I Zw 1
• Black Hole Mass and Eddington Ratio as Drivers for the Observable Properties of Radio-Loud and Radio-Quiet QSOs
• Systematic Effects in Measurement of Black Hole Masses by Emission-Line Reverberation of Active Galactic Nuclei: Eddington Ratio and Inclination
• A Global Three Dimensional Radiation Magneto-hydrodynamic Simulation of Super-Eddington Accretion Disks
• Unification of Luminous Type 1 Quasars through CIV Emission
• Fast Molecular Outflows in Luminous Galaxy Mergers: Evidence for Quasar Feedback from Herschel
• The diversity of quasars unified by accretion and orientation
• Quasar feedback and the origin of radio emission in radio-quiet quasars
• Long-term optical variability properties of the Palomar-Green quasars
• Improved redshifts for SDSS quasar spectra
• CIV 1549 as an Eigenvector 1 Parameter for Active Galactic Nuclei
• The Hard X-ray Spectral Slope as an Accretion-Rate Indicator in Radio-Quiet Active Galactic Nuclei
• The Sloan Digital Sky Survey Reverberation Mapping Project: Technical Overview
• Correcting CIV-Based Virial Black Hole Masses
• The Sloan Digital Sky Survey Reverberation Mapping Project: Sample Characterization
• Continuum and Emission Line Strength Relations for a large Active Galactic Nuclei Sample
• Mean Spectral Energy Distributions and Bolometric Corrections for Luminous Quasars
• Systematic Errors in the Estimation of Black Hole Masses by Reverberation Mapping
• X-ray Insights into the Nature of PHL 1811 Analogs and Weak Emission-Line Quasars: Unification with a Geometrically Thick Accretion Disk?
• High-Redshift SDSS Quasars with Weak Emission Lines
• A global view of the inner accretion and ejection flow around super massive black holes: radiation driven accretion disk winds in a physical context
• Global Radiation Magneto-hydrodynamic Simulations of Sub-Eddington Accretion Disks around Supermassive Black Holes
• Quasars as standard candles I: The physical relation between disc and coronal emission
• On the variability of quasars: a link between Eddington ratio and optical variability?
• The Lick AGN Monitoring Project: Recalibrating Single-Epoch Virial Black Hole Mass Estimates
• The Sloan Digital Sky Survey Reverberation Mapping Project: First Broad-line Hbeta and MgII Lags at z>~0.3 from six-Month Spectroscopy
• Average UV Quasar Spectra in the Context of Eigenvector 1: A Baldwin Effect Governed by Eddington Ratio?
• The Sloan Digital Sky Survey Reverberation Mapping Project: Initial CIV Lag Results from Four Years of Data
• BAL and non-BAL quasars: continuum, emission and absorption properties establish a common parent sample
• On the origin of the C IV Baldwin effect in AGN
• The Color Variability of Quasars
• Spectral variability of quasars from multi-epoch photometric data in the Sloan Digital Sky Survey Stripe 82
• Detection of Rest-frame Optical Lines from X-shooter Spectroscopy of Weak Emission Line Quasars
• Weak Emission Line Quasars in the Context of a Modified Baldwin Effect
• The average absorption properties of broad absorption line quasars at 800 < lambda_rest < 3000 Å, and the underlying physical parameters
• The correlations between optical/UV broad lines and X-ray emission for a large sample of quasars
• Connecting the X-ray properties of weak-line and typical quasars: testing for a geometrically thick accretion disk
• Coexistence of Gravitationally Bound and Radiation Driven CIV Emission Line Regions in Active Galactic Nuclei
• Mean and Extreme Radio Properties of Quasars and the Origin of Radio Emission
• The CIV Baldwin effect in QSOs from Seventh Data Release of the Sloan Digital Sky Survey
• Improved Spectrophotometric Calibration of the SDSS-III BOSS Quasar Sample
• The Relationship Between the High Energy Continuum and Emission Lines in QSOs: A Low-Redshift Sample
• Probing the Origins of the CIV and Fe Kalpha Baldwin Effect
• X-ray Insights Into Interpreting CIV Blueshifts and Optical/UV Continua
• The Sloan Digital Sky Survey Reverberation Mapping Project: the CIV Blueshift, Its Variability, and Its Dependence Upon Quasar Properties
• Spectral Variability of Quasars in the Sloan Digital Sky Survey. II: The C IV Line
• CIV Emission and the Ultraviolet through X-ray Spectral Energy Distribution of Radio-Quiet Quasars
• Spectral Evolution in High Redshift Quasars from the Final BOSS Sample
• Classification and analysis of emission-line galaxies using mean field independent component analysis
• Steep Hard-X-ray Spectra Indicate Extremely High Accretion Rates in Weak Emission-Line Quasars
• The Effect of Variability on the Estimation of Quasar Black Hole Masses
• Narrow, Intrinsic CIV Absorption in Quasars as it Relates to Outflows, Orientation, and Radio Properties
• The Spectroscopic Signature of Variability in High-Redshift Quasars

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• Examining AGN UV/optical Variability Beyond the Simple Damped Random Walk
• Testing AGN outflow and accretion models with CIV and HeII emission line demographics in z=2 quasars
• What controls the UV-to-X-ray continuum shape in quasars?
• The most luminous blue quasars at 3.0<z<3.3. II. CIV/X-ray emission and accretion disc physics
• Connecting Low- and High-Redshift Weak Emission-Line Quasars via HST Spectroscopy of Ly$\alpha$ Emission
• Gemini Near Infrared Spectrograph -- Distant Quasar Survey: Augmented Spectroscopic Catalog and a Prescription for Correcting UV-Based Quasar Redshifts
• Shedding New Light on Weak Emission-Line Quasars in the C${}_{\mathrm{IV}}$-H$\beta$ Parameter Space
• [OIII] emission in z=2 quasars with and without Broad Absorption Lines
• How does the radio enhancement of broad absorption line quasars relate to colour and accretion rate?
• Connection between Emission and Absorption Outflows through the Study of Quasars with Extremely-High Velocity Outflows
• The Nature of Luminous Quasars with Very Large C IV Equivalent Widths
• X-ray selected broad absorption line quasars in SDSS-V: BALs and non-BALs span the same range of X-ray properties
• A Novel Test of Quasar Orientation
• Probing the Wind Component of Radio Emission in Luminous High-Redshift Quasars
• Shedding the envelope: JWST reveals a kiloparsec-scale [OIII]-weak Balmer shell around a z=7.64 quasar
• Gemini Near Infrared Spectrograph$-$Distant Quasar Survey: the Chandra View
• Can X-ray Observations Improve Optical-UV-based Accretion-Rate Estimates for Quasars?