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: Up, up and away, in the name of science education

Related Stories

Recommended for you

What is the habitable zone?

7 hours ago

The weather in your hometown is downright uninhabitable. There's scorching heatwaves, annual tyhpoonic deluges, and snow deep enough to bury a corn silo.

Galaxy survey to probe why the universe is accelerating

8 hours ago

We know that our universe is expanding at an accelerating rate, but what causes this growth remains a mystery. The most likely explanation is that a strange force dubbed "dark energy" is driving it. Now a ...

Early Titan was a cold, hostile place for life

8 hours ago

Titan is a mysterious orange-socked moon of Saturn that is exciting to astrobiologists because it has some of the same kinds of chemicals that were precursors to life on Earth. It also has a hydrological ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.