Mystery gamma-ray source pinned to vampire stars

0 Comments | AFP, January, 2008

PARIS (AFP) — An intriguing source of gamma rays linked to the high-energy collision of fundamental particles in the centre of our galaxy has been traced to vampire-like binary stars, a study says.

The big smash comes from negatively-charged electrons colliding with their corresponding positively-charged "antiparticle," known as positrons.

When electrons and positrons meet, the event is very brief, for they destroy -- "annihilate" -- each other in a flash of energy.

In 1970s, astronomers discovered a narrow blast of electron-positron annihilation emanating from near the centre of the Milky Way, detectable in the 511 kiloelectron volt (keV) range of gamma-ray energy.

But the source of the phenomenon has been strongly debated.

Some...