Variability of QSOs with variable regions in broad absorption troughs from the Sloan Digital Sky Survey

Abstract

The variability of broad absorption lines is investigated for a sample of 188 broad-absorption-line (BAL) quasars (QSOs) ($z>1.7$) with at least two-epoch observations from the Sloan Digital Sky Survey Data Release 7 (SDSS DR7), covering a time-scale of about 0.001 -- 3 years in the rest frame. Considering only the longest time-scale between epochs for each QSO, 73 variable regions in the \civ BAL troughs are detected for 43 BAL QSOs. The proportion of BAL QSOs showing variable regions increases with longer time-interval than about 1 year in the rest frame. The velocity width of variable regions is narrow compared to the BAL-trough outflow velocity. For 43 BAL QSOs with variable regions, it is found that there is a medium strong correlation between the variation of the continuum luminosity at 1500 Å and the variation of the spectral index. With respect to the total 188 QSOs, larger proportion of BAL QSOs with variable regions appears bluer during their brighter phases, which implies that the origin of BAL variable regions is related to the central accretion process. For 43 BAL QSOs with variable regions, it is possible that there is a negative medium strong correlation between the absolute variation of the equivalent width and the \mgii-based black hole mass, and a medium strong correlation between the maximum outflow velocity of variable regions and the Eddington ratio. These results imply the connection between the BAL-trough variation and the central accretion process.

arXiv comment15 pages, 9 figures, 3 tables, accepted by MNRAS

References in corpus (39)

• The Sloan Digital Sky Survey: Technical Summary
• Unified Schemes for Radio-Loud Active Galactic Nuclei
• Observational Evidence of AGN Feedback
• Composite Quasar Spectra From the Sloan Digital Sky Survey
• A Catalog of Quasar Properties from SDSS DR7
• Dynamics of line-driven disk winds in Active Galactic Nuclei
• The Relationship Between Luminosity and Broad-Line Region Size in Active Galactic Nuclei
• A Structure for Quasars
• The Radius-Luminosity Relationship for Active Galactic Nuclei: The Effect of Host-Galaxy Starlight on Luminosity Measurements II. The Full Sample of Reverberation-Mapped AGNs
• A Catalog of Broad Absorption Line Quasars from the Sloan Digital Sky Survey Third Data Release
• A Catalog of Broad Absorption Line Quasars in Sloan Digital Sky Survey Data Release 5
• The Sloan Digital Sky Survey quasar catalog: tenth data release
• A strong redshift dependence of the broad absorption line quasar fraction
• Broad Absorption Line Variability on Multi-Year Timescales in a Large Quasar Sample
• Quasars and the Big Blue Bump
• A Systematic Analysis of Fe II Emission in Quasars: Evidence for Inflow to the Central Black Hole
• Quasar Broad Absorption Line Variability on Multi-Year Time Scales
• Broad Absorption Line Disappearance on Multi-Year Timescales in a Large Quasar Sample
• Spectral Variability of Quasars in the Sloan Digital Sky Survey. I: Wavelength Dependence
• Variability in Quasar Broad Absorption Line Outflows I. Trends in the Short-Term versus Long-Term Data
• Outflows and the Physical Properties of Quasars
• Broad Absorption Line Variability in Repeat Quasar Observations from the Sloan Digital Sky Survey
• Variability in quasar broad absorption line outflows II. Multi-epoch monitoring of SiIV and CIV BAL variability
• Variability in Quasar Broad Absorption Line Outflows III. What Happens on the Shortest Time-scales?
• The correlations between optical variability and physical parameters of quasars in SDSS Stripe 82
• Spectral variability of quasars from multi-epoch photometric data in the Sloan Digital Sky Survey Stripe 82
• The Sloan Digital Sky Survey Reverberation Mapping Project: Rapid CIV Broad Absorption Line Variability
• Emission Line Properties of the Large Bright Quasar Survey
• The average absorption properties of broad absorption line quasars at 800 < lambda_rest < 3000 Å, and the underlying physical parameters
• Radio spectra and polarisation properties of radio-loud Broad Absorption Line Quasars
• The CIV Baldwin effect in QSOs from Seventh Data Release of the Sloan Digital Sky Survey
• Radio spectra and polarisation properties of a bright sample of Radio-Loud Broad Absorption Line Quasars
• Orientation effects in quasar spectra: The broad- and narrow-line regions
• BAL QSOs and Extreme UFOs: the Eddington connection
• Biases in the Quasar Mass-Luminosity Plane
• Spectral variability of FIRST bright QSOs with SDSS observations
• The relation between the optical spectral slope and the luminosity for 17 Palomar-Green QSOs
• Variability of broad absorption lines in a QSO SDSS J022844.09+000217.0 on multi-year timescales
• The spectral variability of quasar SDSS J030639.57+000343.1

Cited by in corpus (14)

• Variation of ionizing continuum: the main driver of Broad Absorption Line Variability
• The properties of broad absorption line outflows based on a large sample of quasars
• Multi-Epoch Observations of Extremely High-Velocity Emergent Broad Absorption
• The Sloan Digital Sky Survey Reverberation Mapping Project: Systematic Investigations of Short-Timescale CIV Broad Absorption Line Variability
• Emergence and Variability of Broad Absorption Line Quasar Outflows
• Narrow absorption lines complex I: one form of broad absorption line
• The correlated variations of C IV narrow absorption lines and quasar continuum
• Saturation Effect on Photoionization-driven Broad Absorption Line Variability
• Extreme Variability in a Broad Absorption Line Quasar
• Appearance vs Disappearance of broad absorption line troughs in quasars
• Evidence for Fluorescent Fe II Emission from Extended Low Ionization Outflows in Obscured Quasars
• Time variability of ultra-fast BAL outflows using SALT: C IV equivalent width analysis
• A sharp rise in the detection rate of broad absorption line variations in a quasar SDSS J141955.26+522741.1
• Discovery of the Asymmetric Effect in the Response of Photoionization Gas