Ionization driven intrinsic absorption line variability of BAL quasars in the Stripe 82 region. (arXiv:1904.02149v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+Vivek_M/0/1/0/all/0/1">M. Vivek</a>
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 ~ 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 ~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 ~ 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.
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 ~ 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 ~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 ~ 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.
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