An Exploratory Chandra Survey of a Well-Defined Sample of 35 Large Bright Quasar Survey Broad Absorption Line Quasars

Abstract

We present 4-7 ks Chandra observations of 35 Broad Absorption Line (BAL) quasars from the Large Bright Quasar Survey, the largest sample of sensitive, 0.5-8.0 keV X-ray observations of this class of quasars to date. The limited ranges in both redshift (z=1.42-2.90) and UV luminosity (a factor of ~12) of the sample also make it relatively uniform. Of 35 targets, 27 are detected for a detection fraction of 77%, and we confirm previous studies that find BAL quasars to be generally X-ray weak. Five of the eight non-detections are known low-ionization BAL quasars, confirming reports of extreme X-ray weakness in this subset (~10% of optically selected BAL quasars). Those BAL quasars with the hardest X-ray spectra are also the X-ray weakest, consistent with the interpretation that intrinsic absorption is the primary cause of X-ray weakness in this class of quasars as a whole. Furthermore, the observed trend is not consistent with simple neutral absorption, supporting findings from spectroscopic observations of individual targets that BAL quasars typically exhibit complex X-ray absorption (e.g., partially covering or ionized absorbers). In sum, high-ionization BAL quasars are typically neither intrinsically X-ray weak nor suffer from Compton-thick absorption. In general, we find no evidence for correlations between X-ray weakness and UV absorption-line properties, with the exception of a likely correlation between the maximum outflow velocity of CIV absorption and the magnitude of X-ray weakness. We discuss the implications of our results for disk-wind models of BAL outflows in quasars. (abridged)

21 pages, uses emulateapj, 11 figures (3 color), ApJ accepted

Cited by in corpus (25)

• The Sloan Digital Sky Survey Quasar Catalog IV. Fifth Data Release
• A Cosmological Framework for the Co-Evolution of Quasars, Supermassive Black Holes, and Elliptical Galaxies: II. Formation of Red Ellipticals
• The X-ray Properties of the Most-Luminous Quasars from the Sloan Digital Sky Survey
• A Catalog of Broad Absorption Line Quasars in Sloan Digital Sky Survey Data Release 5
• On the Fraction of Quasars with Outflows
• Quasar Broad Absorption Line Variability on Multi-Year Time Scales
• The Toroidal Obscuration of Active Galactic Nuclei
• Outflows and the Physical Properties of Quasars
• Observational Constraints on the Dependence of Radio-Quiet Quasar X-ray Emission on Black Hole Mass and Accretion Rate
• Emergence of a Broad-Absorption-Line Outflow in the Narrow-line Seyfert 1 Galaxy WPVS 007
• X-ray Properties of Intermediate-mass Black Holes in Active Galaxies
• Radio Through X-ray Spectral Energy Distributions of 38 Broad Absorption Line Quasars
• Evolution of the X-ray Emission of Radio-Quiet Quasars
• Environments of z>5 quasars: searching for protoclusters at submillimetre wavelengths
• The Correlation between X-ray and UV Properties of BAL QSOs
• On the absorption of X-ray bright broad absorption line quasars
• A sensitive submillimetre survey of Broad Absorption Line quasars
• Exploratory Study of the X-Ray Properties of Quasars With Intrinsic Narrow Absorption Lines
• A Chandra Survey of the X-ray Properties of Broad Absorption Line Radio-Loud Quasars
• Chandra Observations of Red Sloan Digital Sky Survey Quasars
• XMM observations of BAL Quasars with polar outflows
• Properties of X-ray selected Broad Absorption Line Quasars
• A Self-Consistent NLTE-Spectra Synthesis Model of FeLoBAL QSOs
• Hubble Space Telescope Ultraviolet Spectroscopy of Fourteen Low-Redshift Quasars
• Physical and kinematical properties of the X-ray absorber in the broad absorption line quasar APM 08279+5255