April 19, 2012
Where in Universe Do Cosmic Rays Come From?
Jason Palmer, BBC News
The mystery surrounding the source of the highest-energy particles known in the Universe has grown deeper.
The particles, known as cosmic rays, can show up with energies a million times higher than the biggest particle accelerators on Earth can produce.
Astrophysicists believed that only two sources could make them: supermassive black holes in active galaxies, or so-called gamma ray bursts.
TAGGED: supermassive black holes, gamma-ray bursts, cosmic rays