Yo Gamma Gamma
Don’t you love a story where even scientists are “perplexed”?
Strange gamma-ray objects perplex scientists
The universe is filled with high-energy radiation, much of which is made of gamma rays belched out by strange pulsing stars and the remnants of supernova explosions. But a new study of some of most extreme objects has turned up a mystery: nearly one-third of all gamma-ray emitting objects seen to date defy identification.
The objects were spotted by NASA’s Fermi Gamma-ray Space Telescope, which scans the entire sky over the course of three hours, mapping the powerful spectrum. When stacked together, the surveys create an extremely precise view of the gamma-ray universe.
Scientists then match these images to other observations to identify each source. But the identities of some gamma-ray sources in space still continue to elude the astronomers.
“There’s some that, despite all our efforts, we really do not know what they are,” David Thompson, Fermi’s deputy project scientist, told SPACE.com. “They do not seem to be any of the usual suspects.” [ Video: Mystery of Fermi’s Gamma-Ray Objects ]
The cosmic detective
The Fermi space telescope has spotted nearly 500 powerful gamma-ray sources in deep space over the last three years. Before its launch in 2008, scientists only knew of four such objects.
“We’re not looking for the ordinary things,” Thompson said. “We’re looking for the extraordinary; powerful things that might produce gamma rays.”
Of the newly discovered bodies, more than half are active galaxies. Pulsars and supernova remnants each make up about 5 percent of the sources, with high-mass binary stars and other galaxies contributing just a smidge more, the researchers said.
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