New Results on Quasar Outflows

A subset of quasars display broad, blueshifted absorption lines in their rest-frame ultraviolet spectra that trace high-velocity outflows that are probably ubiquitous but seen in absorption along only selected lines of sight. These outflows may play a crucial role in removing angular momentum from material that undergoes accretion onto a central black hole, thereby powering these systems. The physical properties of these outflows remain poorly defined. Studies of variability in quasar broad absorption lines provide a promising means of improving physical constraints on these sources. New results on broad absorption line variability will be presented and their implications discussed.