Halo Around Pulsar Could Answer Mystery of Antimatter
Larger than the Big Dipper as seen from Earth, a faint halo surrounding an energetic dead star could answer one of the great mysteries of cosmic rays and help reveal the behavior of pulsars.
The Fermi Space Telescope, launched in 2008, first recorded a faint haze of high-energy light around a nearby stellar corpse called a pulsar. Now, a new analysis of the data suggests this object may play a critical role in the production of the cosmic rays which bathe our Solar System.
Pulsars are the remains of massive dead stars, which emit powerful beams of radiation that, under ideal conditions, can be seen from Earth. One of these stellar corpses, Geminga (geh-MING-ga), was recently found to be encompassed by an enormous, although tenuous, region of high-energy radiation.
If it were possible to see this haze of light with the human eye, it would stretch 20 degrees across the night sky — as large as 40 full moons, lined up side-by-side.
“Our analysis suggests that this same pulsar could be responsible for a decade-long puzzle about why one type of cosmic particle is unusually abundant near Earth. These are positrons, the antimatter version of electrons, coming from somewhere beyond the solar system,” said Mattia Di Mauro, an astrophysicist at NASA’s Goddard Space Flight Center.
