SA part of pioneering experiment

Johannesburg, 12 May 2008

SA's Hartebeesthoek Radio Astronomy Observatory (HartRAO) this week took part in an experiment that tied its radio astronomy dish to others in Europe and the Americas.

This created an intercontinental "super scope" to study quasars as part of a three-year research project.

The Very Long Baseline Interferometry (VBLI) experiment saw a HartRAO dish linked up with observatories in Poland, Sweden, Italy, the UK - and even briefly to the Arecibo dish in Puerto Rico (near Cuba in the Americas) to form a giant virtual telescope.

HartRAO director professor Roy Booth says this was done by sharing data between the devices at a data transfer rate of 32Mbps over the Internet. "This real-time VLBI collaboration is known as e-VLBI.

"VLBI is a technique used by radio astronomers to image the sky with ultra-high resolution and in great detail, including the most distant and faintest regions in space, where we find the enigmatic quasars."

Booth says more transatlantic e-VLBI experiments are planned for the months ahead as part of an Express Production Real-time e-VLBI Service (Expres) experiment. Expres is a three-year project funded by the European Commission with the objective of creating a distributed, large-scale astronomical instrument of continental and intercontinental dimensions.

Instead of using a single radio dish, arrays of telescopes are linked together around the globe to create a more powerful and more sensitive instrument. The longer the baselines, the more detail can be discerned. Booth says this is why the baseline to SA is important and why European astronomers want to use the South African facility.

"This is an exciting glimpse of future radio astronomy," says Booth. "We will be able to observe unpredictable and unusual astronomical phenomena as they happen."

In the past, VLBI data had to be recorded on tape and shipped to a central processing facility for analysis that could take several months, he explains. "Now, with e-VLBI, the world's astronomers are analysing events as they happen. With the new high-bandwidth connection at HartRAO, SA is able to take part in this cutting-edge astronomy."

SA's participation follows in the wake of HartRAO superfast broadband connectivity through the Department of Science and Technology and the CSIR's Meraka Institute.

Expres is coordinated by Jive, the Joint Institute for VLBI in Europe, which is hosted by the Netherlands Foundation for Research in Astronomy, in Dwingeloo, the Netherlands.