Centaurus A black hole jets
The enormous energy output of galaxies like Cen A comes from gas falling toward a black hole weighing millions of times the sun's mass. Through processes not fully understood, some of this infalling matter is ejected in opposing jets at a substantial fraction of the speed of light. Detailed views of the jet's structure will help astronomers determine how they form.
The jets strongly interact with surrounding gas, at times possibly changing a galaxy's rate of star formation. Jets play an important but poorly understood role in the formation and evolution of galaxies.
Image Source: http://www.nasa.gov/topics/universe/features/radio-particle-jets.html