Square Kilometre Array
Other Information
The SKA project website (www.skatelescope.org) has a brochure about the SKA available for download (5.67 MB PDF).
The website of the Australian SKA Project (anzSKA) is www.ska.gov.au.
The SKA will be the biggest radio telescope ever built, with a collecting area two orders of magnitude larger than the current technology. This will be achieved by creating a large array of antenna stations and dispersing them over an area up to 3000 km, with half of the stations being within a 5 km radius. Not only will the sensitivity of the SKA revolutionise discoveries made with radio astronomy, its huge span of antenna also ensures an angular resolution that will be able to detect faint emissions from galaxies much farther away than current technology allows.
Cradle of Life
This high angular resolution will also help achieve one of five key objectives drawn up by the radio astronomy community, titled "Cradle of Life". This involves looking inside the dust rings of young stars to determine how other earth-like planets form, and being able to detect any sources of radio transmissions could confirm intelligent life in the universe.
Probing the Dark Ages
The second project titled "Probing the Dark Ages" uses the method of analysing HI emissions throughout the universe to much further depths with the increased sensitivity. It is widely believed that the SKA could be sensitive enough to reach the epoch of reionization, the onset of star and galaxy formation. This also ties in closely with the fifth project, focussing on the evolution of the stars and galaxies. This can be seen in the figure below which demonstrates a current model of how the universe has evolved.
Above: A computer model of how the HI universe has evolved. (Steve Furlanetto et al 2003, MNRAS)
The Origin and Evolution of Cosmic Magnetism
Also, by being able resolve much more detail of the galaxies, monitoring magnetic fields can lead to answering many fundamental questions of magnetism in general, such as determining if the overall Universe is magnetic. This ability ties into the third major goal, "The Origin and Evolution of Cosmic Magnetism", whereby studies of the Faraday rotation of cosmic signals could help determine the abundance of magnetism amongst the stars.
Strong Field Tests of Gravity Using Pulsars and Black Holes
As the name suggests, the fourth project, "Strong Field Tests of Gravity Using Pulsars and Black Holes" deals with observations of Pulsars and Black holes. By having the increased sensitivity of the SKA, radio astronomers will be able to find Pulsars neighbouring black holes, and use precise timing of the spins to help test Einstein’s general relativity theory with much stronger fields. This excellent timing resolution will also be able to accurately measure millisecond pulsars leading to the detection of passing gravity waves.
Final key project
The final key project for the SKA is "Galaxy evolution, cosmology and dark energy", involving the detection of 21cm HI emissions of many more galaxies in much more detail. By mapping these detections to their redshift (from the observed wavelengths), radio astronomers will also be able to map out the universe with much more accuracy and develop a pattern for clustering of galaxies.
Although each of these projects are the main driving force behind the construction of the Square Kilometre Array, a device of such high sensitivity and resolution is set to make many discoveries in all fields of astronomy. This natural step in radio astronomy technology, however, is long overdue, as the collecting area of optical telescopes are constantly being upgraded with little been done with those designed to measure radio frequencies.
This large advancement in technology raises many questions regarding new antenna for the SKA, with many institutions around the world putting forward design concepts.
One of the more important questions surrounding the implementation of this billion dollar project is its location. From six bids received by countries all around the world, the two remaining are Australia and South Africa. Despite this, it seems likely that Australia will host the SKA when the ISSA announces its location in 2011. Australia is extremely suitable for such a project as it has not only vast amounts of space with little Radio Frequency Interference (RFI), but also its current political and financial stability proves to be attractive to all those involved in the SKA development.
