Work begins on the world's largest cosmic ray observatory

Sep 25, 2012 by Jenny Winder, Universe Today
Lake Baikal. Credit: SeaWiFS Project NASA/Goddard Space Flight Center and ORBIMAGE

Construction has just begun at the Tunka Valley near Lake Baikal, Siberia, Russia on an observatory that, once completed, will consist of an array of up to 1,000 detectors covering 100 square kilometres. Its size will allow scientists to investigate cosmic rays—the space radiation emitted from gamma rays and heavier nuclei—which are accelerated to energies higher than those achieved in the Large Hadron Collider. With the new observatory, called HiSCORE (Hundred Square-km Cosmic ORigin Explorer), scientists hope to solve the mystery of the origins of cosmic rays, and perhaps probe dark matter too

It was a hundred years ago that Austrian-American physicist Victor Hess first discovered that radiation was penetrating Earth's atmosphere from outer space. The problem has been to track down their origin, as cosmic rays consist of charged particles and are therefore deflected in interstellar and intergalactic magnetic fields. The use of simple, inexpensive detector stations, placed several hundred meters apart, makes it possible to instrument a huge area, allowing scientists to investigate cosmic rays within an energy range from 100 TeV up to at least 1 EeV.

Cherenkov detector in front of the starry sky. Credit: Tunka Collaboration

Cosmic rays cannot penetrate our atmosphere but each detector can observe the radiation created when cosmic rays hit the Earth's upper atmosphere, causing a shower of that travel faster than the speed of light in air, producing Cherenkov radiation in the process. This light is weak, but can be detected on the surface of the earth with sensitive instruments like HiSCORE's photomultiplier tubes.

Cherenkov radiation can be used to determine the source and intensity of cosmic rays as well as to investigate the properties of high-energy astronomical objects that emit like and blazars. The wide field of view also allows HiSCORE to monitor extended gamma ray emitting structures such as molecular gas clouds, dense regions or large scale structures such as star forming regions or the galactic plane.

HiSCORE can also be used for testing theories about Dark Matter. A strong absorption feature is expected around 100 TeV. Examination can give information about the absorption of gamma rays in the interstellar photon fields and the CMB. If the absorption is less than expected, this might indicate the presence of hidden photons or axions. Also, the decay of heavy supersymmetric particles might be detectable by HiSCORE. The data will improve as the facility grows over the years. By 2013-14 the area will be around one square kilometre, and over 10 square kilometres by 2016.

HiSCORE is a joint project between the Institute for Nuclear Research of the Russian Academy of Sciences in Moscow, Irkutsk State University in Siberia and Lomonosov Moscow State University – as well as DESY, the University of Hamburg and the Karlsruhe Institute of Technology in Germany. HiSCORE also hopes to collaborate with the Pierre Auger observatory in Argentina.

Explore further: Fermi satellite detects gamma-rays from exploding novae

More information: Find out more about HiSCORE at the project's website.

add to favorites email to friend print save as pdf

Related Stories

Galactic Center Found To Glow Unevenly

Feb 21, 2006

An international team of more than 100 astrophysicists said they have detected very-high-energy gamma rays emanating from the huge gas clouds known to pervade the center of the Milky Way galaxy.

100 years of cosmic rays mystery

Aug 01, 2012

As physicists gather in early August to celebrate a century since the initial discovery of cosmic rays, Alan Watson, emeritus professor of physics at the University of Leeds, explains how physicists have gradually revealed ...

Physicists scrutinize the universe with a novel camera

Nov 07, 2011

( -- For the first time, a telescope has been equipped with a camera based on a new technology that uses semiconductors. This instrument will observe the flashes of light that are produced by gamma ...

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 descri ...

Recommended for you

Fermi satellite detects gamma-rays from exploding novae

5 hours ago

The Universe is home to a variety of exotic objects and beautiful phenomena, some of which can generate almost inconceivable amounts of energy. ASU Regents' Professor Sumner Starrfield is part of a team that ...

Image: Hubble serves a slice of stars

12 hours ago

The thin, glowing streak slicing across this image cuts a lonely figure, with only a few foreground stars and galaxies in the distant background for company.

Evidence of a local hot bubble carved by a supernova

Jul 30, 2014

I spent this past weekend backpacking in Rocky Mountain National Park, where although the snow-swept peaks and the dangerously close wildlife were staggering, the night sky stood in triumph. Without a fire, ...

Astronomers measure weight of galaxies, expansion of universe

Jul 30, 2014

Astronomers at the University of British Columbia have collaborated with international researchers to calculate the precise mass of the Milky Way and Andromeda galaxies, dispelling the notion that the two galaxies have similar ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

5 / 5 (1) Sep 26, 2012
How is this the largest, since Auger has 3000sq km?