A multi-epoch spectroscopic study of the BAL quasar APM 08279+5255 II. Emission- and absorption-line variability time lags

Understand

The study of high-redshift bright quasars is crucial to gather information about the history of galaxy assembly and evolution.

• Variability analyses can provide useful data on the physics of the quasar processes and their relation with the host galaxy.
• In this study, we aim at measuring the black hole mass of the bright lensed BAL QSO APM 08279+5255 at $z=3.911$ through reverberation mapping, and at updating and extending the monitoring of its C IV absorption line variability.
• Thanks to 138 R-band photometric data and 30 spectra available over 16 years of observations, we perform the first reverberation mapping of the Si IV and C IV emission lines for a high-luminosity quasar at high redshift.