Colossal Galactic Explosions; Reality-Bending Black Holes; Special Editions; by Sylvain Veilleux, Gerald Cecil and Joss Bland-Hawthorn; 8 Page(s)

Millions of galaxies shine in the night sky, most made visible by the combined light of their billions of stars. In a few, however, a pointlike region in the central core dwarfs the brightness of the rest of the galaxy. The details of such galactic dynamos are too small to be resolved even with the Hubble Space Telescope. Fortunately, debris from these colossal explosions--in the form of hot gas glowing at temperatures well in excess of a million degrees--sometimes appears outside the compact core, on scales that can be seen directly from Earth.

The patterns that this superheated material traces through the interstellar gas and dust surrounding the site of the explosion provide important clues to the nature and history of the powerful forces at work inside the galactic nucleus. Astronomers can now determine what kind of engines drive these dynamos and the effects of their tremendous outpourings on the intergalactic medium.