FIRST Light of CPSR-2

Click on the image above to see the larger version.

On August 10, 2002, a new supercomputer system was installed and commissioned at the Parkes Radio Telescope. Known as the Caltech-Parkes-Swinburne-Recorder, or CPSR-2 for short, the recorder is in fact a high speed supercomputer device that allows astronomers to do extremely high precision timing measurements of pulsars.

Pulsars are the rapidly spinning remains of very massive stars that have exploded in the past. A beam of radio energy emanating from the pole of a pulsar, sweeps past the Earth once per rotation of the star. Each sweep is detected as a radio pulse, hence the name ``pulsar''. It is these pulses that astronomers time very precisely. Of the 1,500 pulsars known, the Parkes Telescope has discovered over 1,000 of them. The Parkes Telescope is truly the King of pulsar discoverers.

CPSR-2 replaces an older unit that has been at the telescope for the past 5 years. The older unit, CPSR-1, used to record onto magnetic tape the equivalent of 110 CD's worth of data for every hour of observing. The tapes were then later shipped to Swinburne University in Melbourne, and processed there with the University's supercomputer system. It often took weeks to get the results and hundreds of high density tapes were used.

The new unit is much more powerful and versatile. It is able to process 6.5 times more data than the older system, which is equivalent to the information on 700 CD's for every hour of observing. It processes the signals as they are received by the telescope in real-time. There is no need to store the enormous amounts of data collected and the results are obtained straight away.

CPSR-2 is a collaboration between astronomers at Swinburne University in Melbourne, Caltech (California Institute of Technology) in the USA, and the Parkes Observatory, operated by the CSIRO's Australia Telescope National Facility.

Swinburne University built the supercomputer cluster that processes the data in real-time. Caltech have built the high speed digitisers, that is, the equipment that converts the signals received by the telescope into a form that the computer can process. The CSIRO operates the Parkes Telescope that makes it all possible.

Why is this significant?

The new system is much more sensitive than the older unit, which allows astronomers to make the most precise timing observations of pulsars ever made. These precise timings allow them to make more rigorous measurements in order to test Einstein's General Theory of Relativity, which is currently the best theory of gravity we have.

First Light

On 10 August 2002, the first observations with the new system were made on the pulsar known as J1141-6545. This pulsar has a relatively strong signal, with a period of 0.393 seconds between pulses.

A PDF document showing the profile of this pulsar is available here.

Dr. Stuart Anderson and Mr. John Yamasaki from Caltech, who designed and built the digitisers, were present at the telescope for the commissioning of the new system.

Astronomers from Swinburne University in Melbourne were also present. They included Prof. Matthew Bailes, Dr. Stephen Ord, Dr. Willem Van Stratten, Mr. Hayden Knight and Mr. Aidan Hotan.

The CPSR 2 supercomputer.

Swinburne PhD Student Mr. Hayden Knight, at the console of the CPSR2 supercomputer. Click on the images to see the larger versions.

John Sarkissian, Operations Scientist, CSIRO Parkes Observatory.

This article appeared in the Parkes Champion Post.