Unlocking Line-Locking Phenomena in Quasars

Line locking of absorption-line systems in quasar spectra is a clear signature of the dynamical importance of radiation pressure force in driving astrophysical flows, with recent findings suggesting that it may be common in objects exhibiting multiple absorption-line systems. In this talk, the phenomena of line-locking will be reviewed, and the physical implications for quasar outflows outlined. Specifically, it will be shown that line-locked systems pose significant challenges to current theories of quasar outflows with implications for the physical mechanisms underlying cloud formation and confinement in the interstellar medium of (active) galaxies.