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Thursday, August 5, 2010
Fermi solves the mystery of gamma ray pulsars
A pulsar is a highly magnetised rapidly spinning neutron star , the dense core remaining aftera supernova explosion.
NASA's Fermi Gamma-ray Space Telescope solves the mystery of previously unidentified gamma-ray sources. Fermi has now uncovered 16 pulsars based on their high energy gamma rays alone.
Fermi can 'feel' the gamma-ray pulsations gives important information about the mechanism behind the emissions. Radio pulsars emit narrow beams of radio waves that sweep around like a lighthouse beacon, bathing the Earth in radiation to enable detections. If the radio beam misses the Earth, the pulsar cannot be detected by radio telescopes, but FermiÕs ability to detect so many radio-quiet gamma-ray pulsars indicates that the gamma-rays are emitted in a beam that is wider and more fan-like than the radio beam.
