On the Scent of a Pre-Historic Particle Accelerator?

Feb 09, 2006

An international team of astrophysicists have used the H.E.S.S. telescopes to uncover the trail of a 10,000 year old supernova at the heart of the Milky Way. In a paper published in Nature (6th February 2006), they describe their discovery of high energy cosmic rays that have been through a cosmic accelerator - such as a supernova.

The H.E.S.S. telescopes in Namibia detect gamma rays, which are released when high energy particles known as cosmic rays collide with clouds of interstellar gas. Giant clouds of hydrogen gas, with more than 50 million times the mass of our Sun exist at the heart of the Milky Way (the galactic centre).

The cosmic rays from here are more numerous and more energetic than those seen throughout the rest of our galaxy. Their numbers are particularly high at the higher energies, suggesting that they have been recently (astronomically speaking) accelerated to high energy, producing corresponding high energy gamma rays when they collide with the cloud material. This is the first time any facility has been sensitive enough to detect that the clouds glow with very high energy gamma rays.

Candidates for such a cosmic accelerator are a stellar explosion (supernova) or a super-massive black hole. The H.E.S.S. team believe that their cosmic rays were created by a supernova that exploded in the last ten thousand years and is still producing a fading signal of new rays.

Dr Jim Hinton, a British scientist involved in the discovery working at Heidelberg, concludes "This is only the first step. We are of course continuing to point our telescopes at the centre of the Galaxy, and will work hard to pinpoint the exact acceleration site I'm sure that there are further exciting discoveries to come"

Dr Paula Chadwick from the University of Durham said "A supernova explosion that took place inside the gas clouds at the centre of the galaxy around 10,000 years ago, looks the most likely source of the particles. Whilst the original event was most likely hidden from view from Earth, we can now see its after-effects in a stream of particles that have been accelerated in the massive explosion."

Source: PPARC

Explore further: Monster galaxies gain weight by eating smaller neighbors

add to favorites email to friend print save as pdf

Related Stories

New energy record set for multilayer-coated mirrors

Sep 12, 2014

Multilayer-coated mirrors, if used as focusing optics in the soft gamma-ray photon energy range, can enable and advance a range of scientific and technological applications that would benefit from the large ...

Exploring the cosmic X-ray background

Sep 12, 2014

You are likely familiar with the cosmic microwave background. This background is a thermal remnant of the big bang. Because of the expansion of the universe, this remnant energy has a temperature of about ...

Cold snap in the tropics

Aug 25, 2014

Tropical glaciers have responded to episodes of cooling in Greenland and the Antarctic over the past 20,000 years, according to a study carried out mainly by researchers at the CNRS, Université Joseph Fourier, ...

Electric sparks may alter evolution of lunar soil

Aug 21, 2014

The moon appears to be a tranquil place, but modeling done by University of New Hampshire and NASA scientists suggests that, over the eons, periodic storms of solar energetic particles may have significantly ...

Recommended for you

Miranda: An icy moon deformed by tidal heating

10 hours ago

Miranda, a small, icy moon of Uranus, is one of the most visually striking and enigmatic bodies in the solar system. Despite its relatively small size, Miranda appears to have experienced an episode of intense ...

User comments : 0