Transient C IV Broad Absorption Lines in radio detected QSOs
  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
\AA), 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.
