Fermi space telescope maps highest-energy gamma rays yet

BBC : Launched in 2008, the Fermi Gamma-Ray Space Telescope scans the entire sky in every direction every three hours, looking for the highest-energy form of light. From data collected during the first three years of operation, researchers have now put together a catalog of sources with energies greater than 10 GeV. Although most of the 514 sources they found are known, some 65 are not—and could turn out to be new astronomical objects. One possible source that has been proposed is a type of dwarf galaxy whose emission of gamma rays could connote the presence of large amounts of dark matter. The catalog “represents another step in what we can do with Fermi, extending our reach in energy in more than an order of magnitude, and being able to see an entirely different picture of the sky,” said Dave Thompson, NASA’s deputy project scientist on the Fermi mission.