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Published online by Cambridge University Press: 03 June 2010
Broad absorption lines (BALs) in quasar spectra identify high-velocity outflows that likely exist in all quasars and could play a major role in feedback to galaxy evolution (e.g., Di Matteo et al. 2005). Studying the variability in these BALs can help us understand the structure, evolution, and basic physical properties of these outflows. We are investigating BAL variability in a sample of 25 luminous quasars at 1.2 < z < 2.9 with multi-epoch observations that cover time scales from less than around a month to 7.7 years in the quasar rest-frame. We investigate changes in the C iv λ1549 BALs, and we see a variety of phenomena, including some BALs that either appeared or disappeared completely and other BALs that did not change at all over the whole observation period.