The KAT-7 telescope, a prototype for the MeerKAT radio telescope array being built by the SKA South Africa team on the Karoo Astronomy Reserve, has achieved a major milestone. All seven of the dishes have now been successfully fitted with “cold” radio receivers, signaling the successful completion of the telescope antennas.
The first astronomical image has already been made using cold receivers on all seven KAT-7 dishes. The radio galaxy Centaurus A, whose intense radio emission is powered by a massive black hole in the centre of the galaxy, was selected for this honour. The resulting image is much more sensitive than the preliminary image made with just four of the KAT-7 dishes fitted with un-cooled receivers in 2010. This improvement is due to both the cooling of the receivers and the availability of all seven dishes of the array.
The radio receivers and all their components are cooled to about 70 Kelvin (i.e. minus 203 Celsius) in order to reduce the “noise” which is inherent in all radio (and TV) receivers. This allows the telescope to see much fainter objects than it would if the receivers and “feeds” operated at room temperature and were not cooled.
Find out more at: www.ska.ac.za