Press Release

New Wide-Field Imager for Astronomy Launched

By SpaceRef Editor
January 9, 2001
Filed under ,

Commonwealth Department of Education,
  Training and Youth Affairs
Anglo-Australian Observatory
Media contact:
David Kemp’s office: Brooke Lord, (02) 6277 7460 or 0419 446 292 Anglo-Australian Observatory: Dr Fred Watson, (02) 6842 6291

Australian astronomers have built themselves one of the world’s best ‘wide-field’ digital cameras, with chips that now outstrip photographic plates, according to the Federal Minister for Education, Training and Youth Affairs, Dr David Kemp.
Dr Kemp today opened the $1.3 million Wide Field Imager at the home of Australia’s leading optical telescopes, Siding Spring Observatory near Coonabarabran, NSW.
"The digital revolution is under way in astronomy," said Dr Kemp. "Photography has been pushed off its pedestal as the best way to take large pictures of the sky."
The Wide Field Imager (WFI) was built by a consortium comprising the Research School of Astronomy and Astrophysics (RSAA) of the Australian National University, the Anglo-Australian Observatory, the University of Melbourne, and engineering firm Auspace Ltd.
"This is an excellent example of Australian institutions collaborating to provide a world-class research instrument," said Dr Kemp.
Like the digital cameras now used for ordinary photography, WFI uses charge-coupled devices (CCDs), but WFI’s CCDs are far larger than any ordinary digital camera. Eight enormous devices are used together, making WFI over thirty times larger than a top-of-the-range ‘ordinary’ digital camera.
Development of the CCDs was a joint project for institutions including the Australian National University, the Anglo-Australian Observatory (AAO), the University of Hawaii, and Lincoln Laboratories in the USA. It was a high-risk, no-guarantee venture that has paid off handsomely, according to Professor Jeremy Mould, Director of the RSAA. "These devices are world-class," he said.
WFI will be used on two telescopes at Siding Spring, the ANU’s 1-m (40-inch) telescope and the 3.9-m (150-inch) Anglo-Australian
Telescope, Australia’s largest optical telescope.
It will become the new ‘workhorse’ for imaging on both telescopes.
"WFI is twenty times more sensitive than a photographic plate," said Dr Chris Tinney, AAO Project Scientist for WFI. "This means that we can see a object of a given brightness four-and-half times further away in the same length of time."
On the AAT the instrument can view a patch of sky 32 arcminutes
across, about the size of the full Moon. "It will be used for large imaging surveys, and to search for rare and exotic objects, like the failed stars called brown dwarfs," said Dr Tinney.
"If you want to find a needle in a haystack, you have to be able to look at a lot of hay at once. The area viewed on the 1-m telescope is even larger — 52 arcminutes across," said Dr Gary Da Costa, the ANU Project Scientist for WFI. Dr Da Costa plans to use the instrument to search for stars in the outermost parts of our Galaxy.
In one of the first pieces of science to be done with WFI, Professor Brian Boyle, Director of the AAO is searching for obscured quasars. "NASA’s Chandra X-ray telescope has been tracing obscured galaxies that may harbour quasars," said Professor Boyle. "WFI will now allow us to study these galaxies more carefully."
In another project, Dr Terry Bridges (AAO) and Professor Ken Freeman (ANU) have started using WFI on the larger telescope to hunt for new planets. They are looking for signs of planets moving across the faces of distant stars in a globular cluster called 47 Tucanae. When a planet moves in front of its star, it should cause the star’s light to dim by about 1.5%.
"With WFI we can see 20,000 stars in one hit," said Dr Bridges. "We have a month to observe them, and we may find up to ten that show signs of planets."
Each wide-field image contains a lot of data. "WFI has forced us to face the experience of handling huge datasets — roughly fifteen gigabytes every night," said Dr Tinney. "New instruments around the world are creating huge datasets, and it’s important astronomers develop the right techniques for handling them."
"The UK astronomy community and the European Southern Observatory are investing heavily in such ‘e-science’ techniques," he added.
Equipment to process WFI data has been funded by a grant of $120,000 through the ARC’s Research Infrastructure (Equipment and Facilities) programme to the ANU, the University of Melbourne and the Anglo- Australian Observatory.
In the coming decade the world will invest more than US $10 billion in astronomy, according to Professor Boyle. "Australia has a very strong record in instrumentation and is in a good position to win contracts for many large projects," said Professor Boyle. "Twenty percent of the Anglo-Australian Observatory’s income is already earned this way," he added.
Photographs of the Minister at the AAT can be found here,

SpaceRef staff editor.