SKA potential revealed
The CSIRO, in conjunction with the Auckland University of Technology and the University of Tasmania, have commissioned a working optical fibre link between their separate radio telescopes, emulating the discovery potential of the planned Square Kilometre Array (SKA).
The fibre link, which allowed the separate installations to act as a single installation, uploaded real time data to be collated and delivered to Curtin University in Perth, which was then processed into a single image.
The link connected six telescopes – ASKAP, three CSIRO telescopes in New South Wales, a University of Tasmania telescope and another operated by the Auckland University of Technology – were used together to observe a radio source that is believed to be two black holes orbiting each other.
The ability to successfully link multiple antennas over large distances is a cornerstone technology of the SKA, which will contain several thousand antennas up to 5500 kilometres apart.
"We now have an SKA-scale network in Australia and New Zealand: a combination of CSIRO and NBN-supported fibre and the existing AARNET and KAREN research and education networks," said SKA Director for Australasia Dr Brian Boyle.
The radio source the astronomers targeted was PKS 0637-752, a quasar that lies more than seven and a half billion light-years away from earth.
This quasar emits a spectacular radio jet with regularly spaced bright spots in it, like a string of pearls. Some astronomers have suggested that this striking pattern is created by two black holes in orbit around each other, one black hole periodically triggering the other to “feed” and emit a burst of radiation.
“It’s a fascinating object, and we were able to zoom right into its core, seeing details just a few millionths of a degree in scale, equivalent to looking at a 10-cent piece from a distance of 1000 km,” said CSIRO astronomer Dr Tasso Tzioumis.
During the experiment Dr Tzioumis and fellow CSIRO astronomer Dr Chris Phillips controlled all the telescopes over the internet from Sydney.
Curtin University’s Professor Steven Tingay and his research team built the system used to process the telescope data. “Handling the terabytes of data that will stream from ASKAP is within reach, and we are on the path to the SKA,” he said.
“For an SKA built in Australia and New Zealand, this technology will help connect the SKA to major radio telescopes in China, Japan, India and Korea.”
AARNet, which provides the data network for Australia’s research institutions, has recently shown that it can implement data rates of up to 40 Gbps on existing fibre networks. That figure is for a single wavelength, and one fibre can support up to 80 wavelengths.