Transient C IV Broad Absorption Lines in radio detected QSOs

Abstract

We study the transient (i.e. emerging or disappearing) C IV broad absorption line (BAL) components in 50 radio detected QSOs using multi-epoch spectra available in Sloan Digital Sky Survey DR10. We report the detectionof 6 BALQSOs having at least one distinct transient C IV absorption component. Based on the structure function analysis of optical light curves, we suggest that the transient absorption is unlikely to be triggered by continuum variations. Transient absorption components usually have low C IV equivalent widths (< 8 Å), high ejection velocities (> 10000 \kms) and typically occur over rest-frame timescales > 800 days. The detection rate of transient C IV absorption seen in our sample is higher than that reported in the literature. Using a control sample of QSOs, we show that this difference is most likely due to the longer monitoring time-scale of sources in our sample while the effect of small number statistics cannot be ignored. Thus, in order to establish the role played by radio jets in driving the BAL outflows, we need a larger sample of radio detected BALs monitored over more than 3 years in the QSO's rest frame. We also find that the transient phenomenon in radio detected and radio quiet BALs does not depend on any of the QSO properties i.e. the Eddington ratio, black hole mass, bolometric luminosity and optical-to-IR colours. All this suggests that transient BAL phenomenon is simply the extreme case of BAL variability.

16 pages, 11 figures, 3 tables, Accepted for publication in MNRAS

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Cited by in corpus (14)

• The Sloan Digital Sky Survey Reverberation Mapping Project: Systematic Investigations of Short-Timescale CIV Broad Absorption Line Variability
• Variability of Low-ionization Broad Absorption Line Quasars Based on Multi-epoch Spectra from The Sloan Digital Sky Survey
• Ionization driven intrinsic absorption line variability of BAL quasars in the Stripe 82 region
• Deceleration of CIV and SiIV broad absorption lines in X-ray bright quasar SDSS-J092345+512710
• Rapidly varying Mg II broad absorption line in SDSS J133356.02+001229.1
• 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
• X-ray and multi-epoch optical/UV investigations of BAL to non-BAL quasar transformations
• Fraction of broad absorption line quasars in different radio morphologies
• Spectroscopic Observations of the Outflowing Wind in the Lensed Quasar SDSS J1001+5027
• The physical constraints on a new LoBAL QSO at z=4.82
• MCMC-based Voigt Profile fitting to a Mini-BAL System in the Quasar UM675
• Hubble Space Telescope Observations of BALQSO Ton 34 Reveal a Connection between the Broad Line Region and the BAL Outflow
• A Comparison of Properties of Quasars with and without Rapid Broad Absorption Line Variability