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.
NASA’s Fermi probes ‘dragons’ of the gamma-ray sky

Mon, Mar 8, 2010
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