Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Biggest ever Gamma Ray search starts in Namibia

28.08.2002


The world’s most sensitive Gamma Ray telescopes are being inaugurated in Namibia (in Southwest Africa) on September 3rd. The High Energy Stereoscopic System (H.E.S.S.), a European/African collaboration in which the UK is a partner, will look for Gamma Rays produced by the most energetic particles in the Universe. The array initially consists of four telescopes, the first of which will become operational next week. This one telescope alone is more sensitive than any other existing ground-based array or telescope working in this particular area of the electromagnetic spectrum.



Once all four telescopes are operational in late 2003, researchers from the University of Durham will use H.E.S.S. to investigate a range of extreme cosmic environments such as the supernova remnants formed when a star dies. A major goal is to see if these are a source of cosmic rays - charged particles that constantly bombard the Earth from space. The origin of cosmic rays is difficult to determine as they are influenced by the magnetic field of our Galaxy. However, the Gamma Rays they emit travel in a straight line, so they may reveal the primary source of the cosmic rays. H.E.S.S. will also be probing the structure of pulsars (rapidly rotating stars formed when a massive star explodes at the end of its life, which emit pulses across the range of the electromagnetic spectrum) and active galactic nuclei to find the source of their energy.

Dr Paula Chadwick, of the Durham team, explains: "H.E.S.S. is set to give us unique insights into some of the most extreme environments in the universe. We have some expectations about what we will be able learn more about - supernova remnants, active galaxies and so on - but experience tells us that when you improve the sensitivity of your telescope, you see things you never expected as well. It`s going to be very exciting!"


When Gamma Rays are absorbed by the Earth’s atmosphere, pairs of electrons and positrons are created and emit tiny flashes of light in a process known as Cherenkov radiation. Telescopes such as H.E.S.S can detect these tiny flashes of light. By using the Earth’s atmosphere as part of the detector, the telescopes have much greater sensitivity than an equivalent space based device, and can detect far fainter Gamma Ray sources than previously possible.

Gamma rays are usually produced by particles moving very rapidly. The study of Gamma Rays enables astronomers to learn more about systems that accelerate these particles, such as active galactic nuclei where supermassive black holes produce jets of particles travelling near the speed of light. These are strong and highly variable sources of gamma rays. Gamma Rays can also be produced by the annihilation of massive particles that may be the source of the ‘missing mass’ in the universe.

The University of Durham’ s role in the design and manufacture of HESS has been in calibrating the camera that will record the Cherenkov radiation and in developing systems that will measure the atmospheric conditions. This is critically important as variations in the atmosphere, such as cloud cover, can dramatically reduce the amount of light reaching the telescopes. The Durham scientists are now working on various refinements to calibration systems, and a more efficient mirror making technique that they hope to use when the array is extended from the current 4 telescopes to the planned 12 or 16.

Namibia is an excellent site scientifically, one of the best in the world for ground-based optical astronomy and with ideal atmospheric conditions for the techniques used by H.E.S.S. However, practically it has represented a huge challenge with limited road access to the site and water, power and computing connections having to be put in place specially.

Julia Maddock | alfa
Further information:
http://www.mpi-hd.mpg.de/hfm/HESS/HESS.html

More articles from Physics and Astronomy:

nachricht Hope to discover sure signs of life on Mars? New research says look for the element vanadium
22.09.2017 | University of Kansas

nachricht Calculating quietness
22.09.2017 | Forschungszentrum MATHEON ECMath

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>