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 ( \rho _ { s } \sim 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 ( \rho _ { s } \sim 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 ( \rho _ { s } \sim 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 .