Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.atnf.csiro.au/people/cjackson/xNTD_Antennas_Sept_05/radioast_sheet_Aug05_3.pdf Дата изменения: Thu Sep 1 05:50:47 2005 Дата индексирования: Sun Dec 23 18:12:33 2007 Кодировка: Поисковые слова: south pole

Radio astronomy and the Square Kilometre Array telescope (SKA)
Stars, galaxies and other cosmic objects give out radio waves as well as light and other radiation. Radio telescopes gather radio waves, just as optical telescopes gather light: astronomers use both kinds of information to learn about the objects in space .

What is radio astronomy?
The radio waves from objects in space tell us about the size, shape and behaviour of the object being studied, what it is made of, and what lies in the space between it and the Ear th. Radio telescopes receive and focus the radio waves, which are then electronically processed so that they can be measured by a computer, and then interpreted by astronomer s.

site of about 5 km in diameter. The other s will be spread over a larger distance, up to 3 000 km (or perhaps more) from the central site.

What will the SKA do?
The SKA will detect the radio waves from distant objects in space, enabling astronomer s to answer many impor tant questions about the Univer se. Because the SKA will have approximately 100 times the collecting area of today's largest radio telescope it will be far more sensitive--able to detect ver y weak signals and form ver y detailed images of astronomical objects. One of the many new things the SKA will be able to do is to `see' ver y distant objects. Radio waves from these objects were emitted in the distant past, and have travelled for a long time to reach Ear th. By studying these waves, the SKA will be able to explore the ear ly histor y of our Univer se .

One possible design for the Square Kilometre Array, in which the individual elements that collect the radio waves are 15-m diameter dishes, grouped into patches 200 metres across. The whole telescope consists of many patches, some separated by thousands of kilometres. Image: Chris Fluke, Centre for Astrophysics and Supercomputing, Swinburne University of Technology

What is the SKA?
The SKA, or Square Kilometre Array telescope, is the `next-generation' radio astronomy telescope. It will have an area for collecting radio waves of roughly one square kilometre, which is about 100 times bigger than today's largest radio telescope. However, the huge collecting area will not be in the form of a single antenna: instead, the radio waves will be collected by many small antennas, and then electronically combined.

Who is involved?
The SKA project is being carried out by a consor tium of 17 countries, including Australia and New Zealand, all wor king jointly on the concept and engineering design. The project is coordinated through an International Project Office (ISPO: www.skatelescope.org). Australia is a major contributor to SKA R&D and plays a significant role in the international project's activities.

What will the SKA look like?
The favoured design for the SKA has as its basic `building block' a close-packed group of small antennas covering an area of a few hundred metres in diameter, and probably no more than 15 metres high. Such a group is called an `arraystation'. The SKA will be made up of many spar sely scattered array-stations. About half the arraystations will be clustered together in a central

When and where will it be built?
Astronomer s plan to design and build the SKA over the fir st two decades of the 21st centur y. The location for the SKA will be decided by the international community before 2009. Australia will be proposing a site centred at Mileura in Western Australia. Other contender s are South Africa, China and Argentina. Contact: Dr Simon Johnston, Australian SKA Planning Office, tel +61-2-9372-4573 Simon.Johnston@csiro.au www.atnf.csiro.au/projects/ska/

Multiple `beams' from the SKA will allow many different astronomical observations to be made simultaneously.

CSIRO
August 2005