Ionization driven intrinsic absorption line variability of BAL quasars in the Stripe 82 region

Abstract

We investigate the connection between the intrinsic C IV absorption line variability and the continuum flux changes of broad absorption line (BAL) quasars using a sample of 78 sources in the Stripe 82 region. The absorption trough variability parameters are measured using the archival multi-epoch spectroscopic data from the Sloan Digital Sky Survey (SDSS), and the continuum flux variability parameters are estimated from the photometric light curves obtained by the SDSS and the Catalina Real-Time Survey (CRTS) surveys. We find evidence for weak correlations (ρ~ 0.3) between the intrinsic C IV absorption line variability and the quasar continuum variability for the final sample of 78 BAL quasars. The correlation strengths improve (ρ~0.5) for the "high-SNR" sample sources that have higher spectral signal-to-noise ratio. Using two sub-sets of the high-SNR sample differing on the absorption trough depth, we find that the shallow trough sub-set shows an even stronger correlation (ρ~ 0.6), whereas the deep trough sub-set does not show any correlation between the absorption line variability and the continuum variability. These results point to the important role of saturation effects in the correlation between the absorption line variability and the continuum variability of BAL quasars. Considering other effects that can also smear the correlation, we conclude that the actual correlation between the absorption line and continuum variability is even stronger.

18 pages, 5 figues, 6 tables, Accepted for publication in MNRAS

References in corpus (18)

• Modeling the Time Variability of SDSS Stripe 82 Quasars as a Damped Random Walk
• The Sloan Digital Sky Survey Quasar Catalog: twelfth data release
• A Catalog of Broad Absorption Line Quasars in Sloan Digital Sky Survey Data Release 5
• SDSS Standard Star Catalog for Stripe 82: the Dawn of Industrial 1% Optical Photometry
• Testing thermal reprocessing in AGN accretion discs
• The Intrinsic Fraction of Broad Absorption Line Quasars
• On the Fraction of Quasars with Outflows
• Quasar Broad Absorption Line Variability on Multi-Year Time Scales
• The Sloan Digital Sky Survey Reverberation Mapping Project: No Evidence for Evolution in the M-sigma Relation to z~1
• Broad Absorption Line Variability in Repeat Quasar Observations from the Sloan Digital Sky Survey
• Emergence of a Broad-Absorption-Line Outflow in the Narrow-line Seyfert 1 Galaxy WPVS 007
• The Sloan Digital Sky Survey Reverberation Mapping Project: Rapid CIV Broad Absorption Line Variability
• Evidence that FeLoBALs may signify the transition between an ultraluminous infrared galaxy and a quasar
• Variation of ionizing continuum: the main driver of Broad Absorption Line Variability
• Correlation between the variation of the ionizing continuum and broad absorption lines
• Emergence of a Quasar Outflow
• Broad Absorption Line Variability in Radio-Loud Quasars
• Evidence for photoionization-driven variability in narrow absorption lines

Cited by in corpus (6)

• Appearance vs Disappearance of broad absorption line troughs in quasars
• Investigating the {Origin} of the Absorption-Line Variability in Narrow-Line Seyfert 1 Galaxy WPVS 007
• Time variability of ultra-fast BAL outflows using SALT: C IV equivalent width analysis
• Fraction of broad absorption line quasars in different radio morphologies
• Transient LoBALs at high velocities: A Case of Extreme Broad Absorption Line Variability in J115636.82+085628.9
• Discovery of the Asymmetric Effect in the Response of Photoionization Gas