NASA's Fermi probes 'dragons' of the gamma-ray sky
Monday, March 15, 2010 - 21:00
in Astronomy & Space
One of the pleasures of perusing ancient maps is locating regions so poorly explored that mapmakers warned of dragons and sea monsters. Now, astronomers using NASA's Fermi Gamma-ray Space Telescope find themselves in the same situation as cartographers of old. A new study of the ever-present fog of gamma rays from sources outside our galaxy shows that less than a third of the emission arises from what astronomers once considered the most likely suspects - black-hole-powered jets from active galaxies...