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From the depths of space, powerful yet enigmatic signals, lasting only thousandths of a second and then vanishing, are tantalising radio astronomers with the prospect there is an unseen and unsuspected face of the universe.
In the quest to isolate and explain these mysterious phenomena, an alliance of Indian and Australian astrophysicists is building a supercharged observation system of the future, capable of interpreting an avalanche of data from the stars, the moment it arrives at Earth. The project is supported by the Australian Government under the Australia-India Strategic Research Fund.
The partnership between Swinburne University of Technology, Western Australia’s Curtin University of Technology, the Australia Telescope National Facility and India’s National Centre for Radio Astrophysics is also laying technological foundations for the proposed Square Kilometre Array (SKA), the gigantic international venture to build the largest and most potent astronomical instrument yet – for which Australia is a candidate host nation.
The alliance will link India’s Giant Metrewave Radio Telescope with up to six Australian instruments and Swinburne’s supercomputer to form a virtual radio telescope spanning half the Earth, says Swinburne astrophysicist Dr Ramesh Bhat.
Dr Bhat says that the science and technology being developed to bring these instruments together and handle the vast quantities of data they produce in real time “will be totally radical. But it is also technology essential to building the SKA.”
One of the alliance’s first assignments is to probe the mysterious and transient radio bursts. These appear to be of two kinds, Dr Bhat says: one sort that repeats at fairly long intervals, which may originate from an exotic form of neutron star, and another that is simply a flash, unexpected and, so far, not detected twice in the same place. “We simply don’t know what these are. They are very powerful but very short – a cosmic mystery,” he admits.
“Taken together, these short bursts indicate to us that there may be another aspect to the universe – the dynamic radio universe – which is so far very poorly known and explored. The plan of our partnership is to explore it,” he says.
The use of India’s powerful metre-wavelength instrument will enable Australian observers to explore the heavens more fully in this less-familiar band of the radio spectrum and at up to 10 times the resolution, promising many fresh discoveries and insights. Another part of the magic in the partnership lies in the use of the Swinburne supercomputer’s powerful resources to develop new software to fuse data from multiple telescopes of this giant instrument into a single device capable of observing the universe continually both in great breadth and extreme detail around the clock.
“Normally, a small radiotelescope can scan a large part of the sky at very low resolution, while a large one can focus on a particular small region with great precision. Ours will do both at once. You have the best of both worlds,” he says. “Futhermore, we will do it by piggybacking on this highly versatile telescope while it is being used by other astronomers, without interfering with their schedule, harvesting our data at the same time as they gather theirs.”
The supercomputer will use clever software to process data flowing from a few actual instruments into the equivalent of several hundred high-resolution radio telescopes, thus emulating a telescope that has many eyes, a technique known as multibeaming. This will enable the team to both continually scan the broad sweep of the heavens for rare events such as the millisecond flashes and be instantly focused on any that occur with the equivalent of hundreds of precision instruments. “With rare events like these you have a real problem in knowing where and when to look,” Dr Bhat says. “The best we can do is to keep looking everywhere, and around the clock, in unprecedented detail.”
Professor Matthew Bailes, director of Swinburne’s Centre for Astrophysics and Supercomputing, says the challenge is that data flowing from the telescopes is so immense it cannot be stored, as every second it would fill about two CDs. “You just can’t afford to store these data and process them offline. You have to be able to analyse them as they are captured,” he says.
The Swinburne team visited India in October and is impressed with the data collected so far. “The new software backend is exceeding our expectations. Observations of known pulsars are allowing the highest fidelity observations ever undertaken at these frequencies and promise a treasure trove of science. This collaboration will reveal the true power of the giant Indian telescope”.
“Every country has an interest in the SKA project and it is not something that one country can do alone. This project will strengthen the ties between India and Australia in astronomy, which is very important, as these two countries are among the key partners in the SKA project,” Professor Bailes says.
This project is supported by the Australian Government under the Australia-India Strategic Research Fund.
A story provided by Swinburne Magazine. This article is under copyright; permission must be sought from Swinburne Magazine to reproduce it.
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