Space and Earth Sciences News

A new class of pulsars detected by NASA's Fermi Gamma-ray Space Telescope is solving the mystery of previously unidentified gamma-ray sources and helping scientists understand the mechanisms behind pulsar emissions.A study to be published by an international team of scientists in the July 2 edition of Science Express describes 16 pulsars discovered by Fermi based on their pulsed emissions of high-energy gamma rays.

"These are the first pulsars ever detected by gamma rays alone, and already we've found 16," said coauthor Robert Johnson, professor of physics at the University of California, Santa Cruz. "The existence of a large population of radio-quiet pulsars was suspected prior to this, but until Fermi was launched, only one radio-quiet pulsar was known, and it was first detected in x-rays."
"From the faintest pulsar we studied, the LAT sees only two gamma-ray photons a day," Ziegler said.
"It's been a longstanding question what could be powering those unidentified sources, and the new Fermi results tell us that a lot of them are pulsars," Saz Parkinson said. "These findings are also giving us important clues about the mechanism of pulsar emissions."
"This favors models in which the gamma rays are emitted from the outer magnetosphere of the pulsar, as opposed to the polar cap much closer to the surface of the star," Saz Parkinson said.
"Fermi has truly unprecedented power for discovering and studying gamma-ray pulsars," said Paul Ray of the Naval Research Laboratory in Washington.