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This image shows a spiral galaxy and a
nebulous object in the Capodimonte Deep Field. The field shown covers
1250 x 750 pixels, or about 5 x 3 arcmin 2 in the sky. Note the very
red objects next to the two bright stars in the lower-right corner.
The colours of these objects are consistent with those of spheroidal
galaxies at intermediate distances (redshifts).
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Australia’s newest radio telescope is
predicted to find an unprecedented 700,000 new galaxies, say
scientists planning for CSIRO’s next-generation Australian Square
Kilometre Array Pathfinder (ASKAP).
In a paper to be published Sunday in
the Monthly Notices of the Royal Astronomical Society, Australian
researchers have combined computer simulations with ASKAP’s
specifications to predict the new telescope’s extraordinary
capabilities.
“Our simulation is similar to testing
a Formula 1 car in a wind tunnel before using it on the track.”
ASKAP will start scanning southern
skies in 2013 as a forerunner to the massive Square Kilometre Array
(SKA), which will be shared between Australia-New Zealand and
Southern Africa.
Dr Duffy said two ASKAP surveys,
WALLABY and DINGO, would examine galaxies to study hydrogen gas - the
fuel that forms stars - and how those galaxies had changed in the
last 4 billion years, allowing us to better understand how our own
galaxy, the Milky Way, grew.
“We predict that WALLABY will find an
amazing 600,000 new galaxies and DINGO 100,000, spread over trillions
of cubic light years of space.”
Dr Duffy said the new ASKAP galaxy
surveys would also allow astronomers to probe the nature of one of
astronomy’s greatest mysteries - Dark Energy.
Combining a large simulation of the
Universe with new theories of galaxy formation − including the
effects of supermassive black holes − had led scientists to
accurately predict where as-yet undiscovered galaxies should be
located, Dr Duffy said.
“We calculated how much of the model
Universe ASKAP could observe using details of the telescope’s
capabilities,” said co-author Dr Baerbel Koribalski, who has
recently been appointed as an Office of the Chief Executive Science
Leader at the CSIRO.
Co-author Associate Professor Darren
Croton from Swinburne University of Technology also said the
predictions would be used to help scientists refine how to handle the
large quantity of data ASKAP will produce and test theories of galaxy
formation.
“If we don't see this many galaxies,
then the Universe is strangely different to our simulations,”
Associate Professor Croton said.
ASKAP will become part of the world’s
largest telescope – the SKA.
ICRAR is a joint venture between Curtin
University and The University of Western Australia providing research
excellence in the field of radio astronomy.
Original Publication:
Dr Alan Duffy et al. “Predictions
for ASKAP Neutral Hydrogen Surveys” Published in the Monthly
Notices of the Royal Astronomical Society, Vol 426 Issue 4.
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