Origin Of Cosmic Rays Pinpointed At Last

Professor Ian Halliday, CEO of PPARC, which funds UK participation in H.E.S.S., said, “These results provide the first unequivocal proof that supernovae are capable of producing large quantities of galactic cosmic rays – something we have long suspected, but never been able to confirm.”

Gamma rays are the most penetrating form of radiation we know, around a billion times more energetic than the X-rays produced by a hospital X-ray machine. This makes it very difficult to use them to create an image – they just pass straight through any surface which we might use to reflect them, for instance. However, luckily for life on Earth, gamma rays from objects in outer space are stopped by the atmosphere; when this happens, a faint flash of blue light is produced, lasting for a few billionths of a second. The astronomers used images of these flashes of light, called Cherenkov radiation, to make a gamma ray ‘image’ for the first time.

Text for this article came from a PPARC press release.