Oxford computer scientists and radio astronomers are working to ensure that computing systems will have the capacity to efficiently process data from the world's most powerful radio telescope, the Square Kilometre Array (SKA), in a way that is both energy and cost efficient.
Using the UK's most powerful GPU-based supercomputer, "Emerald" which was launched in July 2012 at the Rutherford Appleton Laboratory, they are hoping to understand the computational needs required to provide real-time detection of transient events such as single radio bursts or periodic signals from objects such as Pulsars for the SKA project.
This initiative is an essential component of the SKA project and will enable scientists to interpret the complex data as it is received.
SKA is a next generation radio telescope that will allow scientists to test general relativity, gain greater understanding of dark energy and dark matter and also gain insight into the early history of our universe. This will be done by looking for unknown objects in our universe and also studying known ones such as Pulsars.
A pulsar is a highly magnetized, rotating neutron star that emits a beam of electromagnetic radiation. Radio bursts generated by pulsars carry valuable information about the physical processes occurring at the source, as well as in the intervening interstellar or intergalactic medium.
According to Wes Armour, James Martin Fellow at the Institute for the Future of Computing, “Pulsars act as galactic lighthouses and are excellent probes of extreme physical processes originating from compact sources within our galaxy and beyond.”
“The principal aim of SKA and similar experiments is to look for new objects in the universe. However, although the SKA can detect these objects as ‘radio bursts’, there is an added complication. As radio signals move from the object to the telescope they experience a phenomenon called dispersion, a by-product of the distance travelled through the interstellar medium,” he explained.
Scientists don’t know how dispersed any signal will be because they have no idea how far it has travelled and through what parts of the interstellar medium. Hence all potential dispersion values need to be tested. Success in detection and classification depends on fast searches across all possible dispersion measures, which requires dedicated high performance computing based on systems such as Emerald.
SKA will have a total collecting area of approximately one square kilometre. It will operate over a wide range of frequencies and its size will make it 50 times more sensitive than any other radio instrument. It therefore requires very high performance central computing facilities with a network capacity exceeding the current global Internet traffic.
Wes Armour is a member of the Institute for the Future of Computing, based at the Oxford e-Research Centre and is working with Professor Mike Giles on a pathfinder project called MOTIVATE (Many-cOre Technology Investigating Value, Application, deploymenT and Efficiency). The project investigates the application of the latest many-core technologies, including GPUs (graphics processing units) to deliver energy and cost efficiencies in areas such as Radio Astronomy High Performance Computing. Wes Armour and colleagues, Aris Karastergiou and Chris Williams, have incorporated results from this work into the ARTEMIS system which is now being used on leading radio telescopes around the world.
Photo by SKA Project Development Office and Swinburne Astronomy Productions, via Wikimedia Commons