CSIROTechnology behind
World’s Largest Telescope
TheNational AstronomicalObservatories of the Chinese
Academy ofSciences has teamed up with CSIRO engineersto
develop the world’s largest single dish radio telescope. The 500-
metre ApertureSphericalTelescope(FAST) easily dwarfs the
current largest single dishtelescope, the AreciboObservatory
in Puerto Rico. It will also be one of the most sensitive, capable
of receivingweaker andmore distant radio signals, in turn
helping to explore the nature, origins and evolution of the
universe.
The telescope’s19-beam receiver is being designed andbuilt
in Australia by CSIROengineers.“This is a really excitingproject
and builds on40 yearsofCSIROcollaboration with Chinese
industry and research organisations,” saidCSIRO Chief Exec-
utive Dr LarryMarshall.
Most radio telescopes use receivers that can only access one
part ofskyat a time, but CSIRO scientists have designed receivers
with many separate,simultaneous beams,makingit practical
forFASTto search a large portion of theskyfor faint and hidden
galaxies. “The powerful receiver we’ve created forFAST is the
resultof our long history developing cutting-edge astronomy
technology to receive and amplify radio waves from space,” said
Acting DirectorCSIROAstronomy andSpace Science, DrDouglasBock. “Extending our technology and collaboration
to China and working on what will become the world’s largest
radio telescope really cements our position as a global R&D
leader in this space.”
This state-of-the-art instrument will help astronomers expand
their understanding of the universe. FAST will make it possible
for us to look for a range of extremely interesting and exotic
objects, like the thousands of new pulsars in our galaxy, and
perhaps other distant galaxies too.Astronomers at Swinburne
University of Technology
have discovered an
unusually shaped structure
in two nearby disc galaxies.
The distribution of stars
bulging from the centre of
these galaxies’ flattened discs resembles two peanut shells, with one
neatly nested within the other.
“This is the first time such a phenomenon has been observed,” says
Bogdan Ciambur, the PhD student who led the investigation. “We expect
the galaxies’ surprising anatomy will provide us with a unique view into
their pasts. Deciphering their history can tell us about transformations
that galaxies like our own Milky Way might experience.”
The Swinburne team recently developed new imaging software that
make it possible to find the delicate features that led to this discovery.
Using data from the Hubble Space Telescope and the Sloan Digital
Sky Survey, the researchers realised that two of the galaxies they were
studying – NGC 128 and NGC 2549 – displayed a peanut shell
configuration at two separate layers within the three-dimensional
distribution of stars within them.
“Ironically, these peanut-shaped structures are far from peanut-
sized,” says Swinburne Professor Alister Graham, co-author of theresearch. “They consist of billions of stars typically spanning 5–25% of
the length of the galaxies.”
Although the bulges of both galaxies were already known to display
a single peanut shell pattern, astronomers had never before observed
the fainter second structure in any galaxy.
Astronomers think peanut-shaped bulges are linked to a bar-shaped
distribution of stars observed across the centre of many rotating galaxy
discs. The NGC 128 and NGC 2549 galaxies contain two such bars. One
way the peanut-shaped structures may arise is when these bars of stars
bend above and below the galaxy’s central disc of stars.
Ciambur likens this bending to water running through a garden
hose: when the water pressure is low the hose remains still, but when
the pressure is high the hose starts to bend.
“By directly comparing real galaxies with state-of-the-art
simulations, we hope to better understand how galaxies evolve,” says
Ciambur. “The discovery is exciting because we can more fully test the
growth of bars over time, including their lengths, rotation speeds and
periods of instability.”
The study may also shed new light on the peanut-shaped bulge of
our Milky Way galaxy, which some astronomers suspect contains two
stellar bars.
The research has been published in Monthly Notices of the Royal
Astronomical Society(http://tinyurl.com/zqatk7l).JUNE 2016|| 45David Reneke is an astronomy lecturer and teacher, afeature writer for major Australian newspapers and magazines, and a science correspondent for ABC and commercial radio.
Subscribe toDavid’sfree Astro-Space newsletter at http://www.davidreneke.comOUT OF THIS WORLD David RenekeDouble Peanut Shell-Shaped Galaxy Discovered
The 500-metre Aperture Spherical Telescope as it will look upon
completion. Credit: NAOCCredit: B Ciambur