15 September 2008
Hai Fu (Caltech)
"Extended Emission-Line Regions: Remnants of Quasar Superwinds?"
Black holes are not only an integral component of galaxies, but they also appear to have played a
fundamental role in galaxy evolution. It is theorized that galaxy-scale feedback from high-redshift
quasars is key to understanding the properties of the most massive galaxies today. However, direct
observations of the feedback have been lacking. Our observations on the extended nebulae around
low-redshift quasars show that recent quasar-driven superwinds have drastically altered their
environments. The superwind is capable of ejecting most of the interstellar medium to large distances,
demonstrating an efficient mechanism that can regulate both star formation and black hole growth.
Such superwinds provide local analogs of the quasar feedback hypothesized to have happened in the