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Infrared facility in Karoo to probe nearby galaxies

Japanese and South African astronomers are about to start putting together a clearer, sharper picture of the two nearest galaxies to our own (the Magellanic Clouds) and of the central regions of our own Milky Way galaxy. These will be the main targets of surveys with the new InfraRed Survey Facility (IRSF).

The IRSF becomes the seventh telescope at the South African Astronomical Observatory (SAAO) observing site near Sutherland in the Northern Cape. This telescope is the second largest on the site, with a mirror 1.4 metres in diameter. 

"Japan and South Africa have long been partners in building and using infrared cameras for astronomy. This international partnership resulted in the new computerised, hi-tech facility at Sutherland, ushering in an exciting new era for infrared astronomy," says NRF president Dr Khotso Mokhele. Mokhele if officially opening the facility with Prof Shuji Sato, head of the Infrared Group at Nagoya University, Japan. 

"We can't see infrared radiation, but we may feel it as heat. At these wavelengths we can 'see' through dust clouds to regions otherwise hidden from our view," explains SAAO director Dr Bob Stobie. "Infrared light is also ideal for studying cool stars that radiate most of their energy at wavelengths too long for the eye to see," he adds. 

To date, collaboration between Japanese and South African astronomers for infrared observations has mainly involved the 0.75 metre telescope at the SAAO's Sutherland site and a small 0.4 metre telescope at the SAAO in Cape Town. The SAAO is a national research facility managed by the NRF. 

The total construction cost of the IRSF is about R18 million. The SAAO is responsible for the building (R1.1 million), infrastructure and continuing support. Major funding came from the Japanese Ministry of Education. Nagoya University in Japan built the infrared camera (SIRIUS) at a cost of R7 million. University staff worked with an optical company at Kyoto to build the telescope (R10 million), using Russian optics. 

In each infrared survey exposure at Sutherland, an area of the sky (a square about one quarter as wide as the full moon) will be recorded in three different infrared wavebands simultaneously. Previous infrared surveys have covered large areas of sky, while the Sutherland project will record fainter objects, in images four times as sharp


Article by news@NRf

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