The correlations between optical/UV broad lines and X-ray emission for a large sample of quasars

Abstract

We present Chandra observations of 2106 radio-quiet quasars in the redshift range 1.7<z<2.7 from the Sloan Digital Sky Survey (SDSS), through data release fourteen (DR14), that do not contain broad absorption lines (BAL) in their rest-frame UV spectra. This sample adds over a decade worth of SDSS and Chandra observations to our previously published sample of 139 quasars from SDSS DR5 which is still used to correlate X-ray and optical/UV emission in typical quasars. We fit the SDSS spectra for 753 of the quasars in our sample that have high-quality (exposure time $⪆$10 ks and off-axis observation angle <10 arcmin) X-ray observations, and analyze their X-ray-to-optical SED properties (${\alpha }_{ox}$ and $\Delta {\alpha }_{ox}$) with respect to the measured CIV and MgII emission-line rest-frame equivalent width (EW) and the CIV emission-line blueshift. We find significant correlations (at the >99.99% level) between ${\alpha }_{ox}$ and these emission-line parameters, as well as between $\Delta {\alpha }_{ox}$ and CIV EW. Slight correlations are found between $\Delta {\alpha }_{ox}$ and CIV blueshift, MgII EW, and the CIV EW to MgII EW ratio. The best-fit trend in each parameter space is used to compare the X-ray weakness ($\Delta {\alpha }_{ox}$) and optical/UV emission properties of typical quasars and weak-line quasars (WLQs). The WLQs typically exhibit weaker X-ray emission than predicted by the typical quasar relationships. The best-fit relationships for our typical quasars are consistent with predictions from the disk-wind quasar model. The behavior of the WLQs compared to our typical quasars can be explained by an X-ray "shielding" model.

arXiv comment24 pages, 16 Figures

References in corpus (78)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• The Sloan Digital Sky Survey: Technical Summary
• The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
• Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD
• Coevolution (Or Not) of Supermassive Black Holes and Host Galaxies
• The Leiden/Argentine/Bonn (LAB) Survey of Galactic HI: Final data release of the combined LDS and IAR surveys with improved stray-radiation corrections
• SDSS-III: Massive Spectroscopic Surveys of the Distant Universe, the Milky Way Galaxy, and Extra-Solar Planetary Systems
• Composite Quasar Spectra From the Sloan Digital Sky Survey
• A Catalog of Quasar Properties from SDSS DR7
• Some Aspects of Measurement Error in Linear Regression of Astronomical Data
• Astrophysics Source Code Library
• The Sloan Digital Sky Survey Quasar Catalog V. Seventh Data Release
• Dynamics of line-driven disk winds in Active Galactic Nuclei
• The SDSS Quasar Survey: Quasar Luminosity Function from Data Release Three
• Revisiting the Unified Model of Active Galactic Nuclei
• The SDSS-IV extended Baryon Oscillation Spectroscopic Survey: Overview and Early Data
• A Structure for Quasars
• The Fifth Data Release of the Sloan Digital Sky Survey
• The Chandra Deep Field-South Survey: 4 Ms Source Catalogs
• An Empirical Ultraviolet Template for Iron Emission in Quasars as Derived from I Zw 1
• The Chandra Source Catalog
• The X-ray-to-Optical Properties of Optically-Selected Active Galaxies Over Wide Luminosity and Redshift Ranges
• The Sloan Digital Sky Survey Quasar Catalog: Fourteenth Data Release
• Systematic Effects in Measurement of Black Hole Masses by Emission-Line Reverberation of Active Galactic Nuclei: Eddington Ratio and Inclination
• The Sloan Digital Sky Survey Quasar Catalog: twelfth data release
• Unification of Luminous Type 1 Quasars through CIV Emission
• The X-ray Properties of the Most-Luminous Quasars from the Sloan Digital Sky Survey
• Red and Reddened Quasars in the Sloan Digital Sky Survey
• The diversity of quasars unified by accretion and orientation
• Cosmic X-ray Surveys of Distant Active Galaxies: The Demographics, Physics, and Ecology of Growing Supermassive Black Holes
• Bayesian Estimation of Hardness Ratios: Modeling and Computations
• On the Nature of Soft X-ray Weak Quasi-Stellar Objects
• Improved redshifts for SDSS quasar spectra
• The Sloan Digital Sky Survey quasar catalog: ninth data release
• The tight relation between X-ray and ultraviolet luminosity of quasars
• Double-Peaked Low-Ionization Emission Lines in Active Galactic Nuclei
• Correcting CIV-Based Virial Black Hole Masses
• X-ray Spectroscopy of QSOs with Broad Ultraviolet Absorption Lines
• The Sloan Digital Sky Survey Reverberation Mapping Project: Velocity Shifts of Quasar Emission Lines
• X-ray Insights into the Nature of PHL 1811 Analogs and Weak Emission-Line Quasars: Unification with a Geometrically Thick Accretion Disk?
• HST STIS Ultraviolet Spectral Evidence of Outflow in Extreme Narrow-line Seyfert 1 Galaxies: II. Modeling and Interpretation
• Quasars as standard candles I: The physical relation between disc and coronal emission
• The young stellar population in M17 revealed by Chandra
• Broad Absorption Line Disappearance on Multi-Year Timescales in a Large Quasar Sample
• Conference Summary: AGN Physics with the Sloan Digital Sky Survey
• Are Optically-Selected Quasars Universally X-Ray Luminous? X-Ray/UV Relations in Sloan Digital Sky Survey Quasars
• X-ray Emission from Optically Selected Radio-Intermediate and Radio-Loud Quasars
• Are Outflows Biasing Single-Epoch CIV Black Hole Mass Estimates?
• Reverberation Mapping and the Disk Wind Model of the Broad Line Region
• The X-ray properties of $z>6$ quasars: no evident evolution of accretion physics in the first Gyr of the Universe
• A Population of X-ray Weak Quasars: PHL 1811 Analogs at High Redshift
• Extreme-Velocity Quasar Outflows and the Role of X-ray Shielding
• Weak Hard X-ray Emission from Broad Absorption Line Quasars: Evidence for Intrinsic X-ray Weakness
• X-ray and Multiwavelength Insights into the Nature of Weak Emission-Line Quasars at Low Redshift
• Weak Hard X-ray Emission from Two Broad Absorption Line Quasars Observed with NuSTAR: Compton-thick Absorption or Intrinsic X-ray Weakness?
• Weak-Line Quasars at High Redshift: Extremely High Accretion Rates or Anemic Broad-Line Regions?
• 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 X-Ray Variability of a Large, Serendipitous Sample of Spectroscopic Quasars
• Quasar Evolution and the Baldwin Effect in the Large Bright Quasar Survey
• New constraints on the X-ray spectral properties of type 1 AGN
• X-ray Insights into the Nature of Weak Emission-Line Quasars at High Redshift
• Connecting the X-ray properties of weak-line and typical quasars: testing for a geometrically thick accretion disk
• X-Ray Insights Into the Physics of Mini-BAL Quasar Outflows
• Improved Spectrophotometric Calibration of the SDSS-III BOSS Quasar Sample
• Probing the Origins of the CIV and Fe Kalpha Baldwin Effect
• Reverberation Mapping of the Broad Line Region: application to a hydrodynamical line-driven disk wind solution
• CIV Emission and the Ultraviolet through X-ray Spectral Energy Distribution of Radio-Quiet Quasars
• Monte Carlo error analyses of Spearman's rank test
• Differences Between The Optical/Uv Spectra Of X-Ray Bright And X-Ray Faint QSOs
• Steep Hard-X-ray Spectra Indicate Extremely High Accretion Rates in Weak Emission-Line Quasars
• A Chandra Survey of the X-ray Properties of Broad Absorption Line Radio-Loud Quasars
• C IV BAL disappearance in a large SDSS QSO sample
• The X-Ray Properties of the Optically Brightest Mini-BAL Quasars from the Sloan Digital Sky Survey
• The environment of weak emission-line quasars
• X-ray and multi-epoch optical/UV investigations of BAL to non-BAL quasar transformations
• Photoionization Models of the Broad-line Region
• What is the Origin of the Baldwin Effect in the BLR and the NLR?

Cited by in corpus (35)

• The Sloan Digital Sky Survey Quasar Catalog: Sixteenth Data Release
• Revealing the Accretion Physics of Supermassive Black Holes at Redshift z~7 with Chandra and Infrared Observations
• On the Observational Difference Between the Accretion Disk-Corona Connections among Super- and Sub-Eddington Accreting Active Galactic Nuclei
• Testing AGN outflow and accretion models with CIV and HeII emission line demographics in z=2 quasars
• The frequency of extreme X-ray variability of radio-quiet quasars
• HYPerluminous quasars at the Epoch of ReionizatION (HYPERION). A new regime for the X-ray nuclear properties of the first quasars
• An Extreme X-ray Variability Event of a Weak-Line Quasar
• Sensitive Chandra coverage of a representative sample of weak-line quasars: revealing the full range of X-ray properties
• What controls the UV-to-X-ray continuum shape in quasars?
• Characterizing Quasar CIV Emission-line Measurements from Time-resolved Spectroscopy
• The WISSH quasars project XI. The mean Spectral Energy Distribution and Bolometric Corrections of the most luminous quasars
• Chandra and Magellan/FIRE follow-up observations of PSO167-13: an X-ray weak QSO at $z=6.515$
• X-ray properties of dust-obscured galaxies with broad optical/UV emission lines
• Deep XMM-Newton Observations of an X-ray Weak, Broad Absorption Line Quasar at $z=6.5$
• 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
• Correlated time variability of multi-component high velocity outflows in J162122.54+075808.4
• Shedding New Light on Weak Emission-Line Quasars in the C${}_{\mathrm{IV}}$-H$\beta$ Parameter Space
• Wavelength Dependences of the Optical/UV and X-ray Luminosity Correlations of Quasars
• More variable quasars have stronger emission lines
• A Fresh Look at AGN Spectral Energy Distribution Fitting with the XMM-SERVS AGN Sample
• The Nature of Luminous Quasars with Very Large C IV Equivalent Widths
• The WISSH quasars project VII. The impact of extreme radiative field in the accretion disk and X-ray corona interplay
• HYPERION: broad-band X-ray-to-near-infrared emission of Quasars in the first billion years of the Universe
• HYPERION. Shedding light on the first luminous quasars: A correlation between UV disc winds and X-ray continuum
• X-ray selected broad absorption line quasars in SDSS-V: BALs and non-BALs span the same range of X-ray properties
• Photometric Selection of type 1 Quasars in the XMM-LSS Field with Machine Learning and the Disk-Corona Connection
• pop-cosmos: Insights from generative modeling of a deep, infrared-selected galaxy population
• Radio Scrutiny of the X-ray-Weak Tail of Low-Mass Active Galactic Nuclei: A Novel Signature of High-Eddington Accretion?
• Probing the Wind Component of Radio Emission in Luminous High-Redshift Quasars
• X-ray Unveiling Events in a z~1.6 Active Galactic Nucleus in the 7 Ms Chandra Deep Field-South
• Can X-ray Observations Improve Optical-UV-based Accretion-Rate Estimates for Quasars?
• Gemini Near Infrared Spectrograph$-$Distant Quasar Survey: the Chandra View
• A quasar shedding its dust cocoon at redshift 2
• X-Ray Evidence Against the Hypothesis that the Hyper-Luminous z=6.3 Quasar J0100+2802 is Lensed