RSAA News of the Month: June 2004
Siding Spring Anniversary
Celebrating 40 years of Australia's Finest Optical Observatory
Forty years ago the first telescope began operation at the Australian National University's Siding Spring
Observatory, near Coonabarabran, NSW. Today
this telescope, the 40"
reflector, is RSAA's main
imaging telescope. During the 1960's two other telescopes joined the
40", a 16" designed for photometry and a 24" designed
for polarimetry. Photometry measures the brightness and colour of
stars and polarimetry measures the magnetic fields in
space.
Left: The first telescopes on Siding Spring
Left to right, the 16", 24" and 40".
Right: The ANU telescopes today
The rectangular building on the left houses the UNSW Automated Patrol
telescope.
Next to it is the dome of the Uppsala/RSAA Schmidt.
Right of centre is the dome of the 24", next to it the rectangular
"dome" of the 2.3-m.
The 16" dome is just visible behind the 2.3-m and the dome of the
40" is on the far right.
Thirty years ago the largest telescope in Australia, the 4-m Anglo-Australian
Telescope (AAT) was commissioned. The AAT has been one of the most
productive telescopes in the world. It was shortly joined by the 1.2-m
UK Schmidt Telescope (UKST),
one of the most powerful survey telescopes of the era. The AAT and
UKST form the Anglo-Australian
Observatory (AAO).
Twenty years ago, the ANU 2.3-m Advanced
Technology Telescope (ATT) was added to what was now one of the
world's great observatories. The 2.3-m was the first optical telescope
in the world to incorporate a thin mirror, an alt-azimuth mount,
fully-integrated computer control and a coaxially-rotating building in
the one design. It became the prototype of the "new-wave" of
telescope designs. The 2.3-m is currently being upgraded with remote
operating capability.
"Birthday Beauties", the magnificent AAT (30 yo) and ATT (20 yo)
Also at Siding Spring are the 0.5-m Uppsala/RSAA
Schmidt telescope, the University of NSW
Automated Patrol Telescope (APT), and the American Robotic Optical Transit
Search Experiment (ROTSE). Two new telescopes will soon join the
observatory. The 2-m Faulkes
South Telescope will see first light later this year, and
construction of the ANU 1.3-m ultra-wide field Skymapper will commence
shortly.
To celebrate this 40/30/20th anniversary, RSAA hosted an Open Night on
May 28, an Open Day on May 29, and an Anniversary Dinner on the
evening of May 29.
Just before sunset on Open Night, two busloads of visitors gathered at
the summit of Siding Spring. After being greeted by RSAA director
Penny Sackett, they were split into groups and visited the
40", 2.3m, UNSW Automated Patrol Telescope, the AAT and the
Faulkes South telescopes. Astronomers at each telescope explained
their programs and showed the telescopes in operation and
recently-collected data. Members of the Astronomical Society of
Coonabarabran showed visitors the Moon, Jupiter and star clusters
through smaller telescopes. Several hundred visitors from
Coonabarabran and the surrounding region attended Open Day and were
shown every instrument at the observatory.
Dusk on May 28
Visitors assemble on the summit, are split into guided
groups, and move off to inspect telescopes in action.
Among the visitors to Open Day were the Mayor of
Coonabarabran, Peter Shinton, and wife Julie.
They were shown the site by Director Penny Sackett,
discussed the AAT with Prof Ben Gascoigne and Dr Fred Watson,
and were impressed by the new Faulkes Telescope.
The Anniversary Dinner was held at the Coonabarabran Club. Eighty-five
staff and ex-staff of Mt Stromlo and Siding Spring Observatories and
the AAO, plus representatives from the University of NSW and the
Faulkes Telescope Project attended. Highlight was the superb cake from
Michel's Patisserie, decorated with an edible image mosaic of SSO
telescopes.
Scenes from the dinner
A happy crowd, entertaining speakers, a well-stocked buffet, a superb
0.6 x 0.4-m cake,
a Director to slice it, and a great time was had by all.
Many tales of the early days were provided by speakers including
Prof. Ben Gascoigne, the first astronomer to set foot on Siding
Spring; engineer Hermann Wehner, who was involved in the construction
of most of the telescopes; Chris McCowage, who has been with the AAO
since its beginning; Penny Sackett, who leads us into the start of the
next 40 years; and Vince Ford, collector of tales best left untold.
Siding Spring, in its 40th year, is truly one of the world's great
observatories.
Supermassive Black Hole
Explodes a "Galaxy in a Box"
RSAA theoretical astronomers Ralph Sutherland and Geoff Bicknell have
built a working computer model of a galaxy which contains a
supermassive black hole. The hole ejects jets of plasma at near
the speed of light in two giant ‘jets’. The jets are
so powerful that they effectively explode the host galaxy.
The simulations, carried out on the ANU/APAC supercomputing facility,
predict the appearance of what is known as a giant radio galaxy. The
new methods being used allow the astrophysicists to predict how the
radio galaxy will evolve over tens of millions of years.
The models have been compared to the nearest Quasar and powerful radio
Galaxy, Cygnus A. Thanks to the efforts of Drs Sutherland and
Bicknell, astronomers are now able to model and predict the
apprearance of these objects simultaneously in the radio and the x-ray
regime for the first time.
An X-ray image of the Cygnus A radio galaxy
showing the expanding ‘fireball’ of superheated plasma.
The image is from NASA's Chandra X-ray Observatory.
ANU supercomputer simulation of a similar galaxy
showing the thermal emission from the hot gas.
A radio image of Cygnus A from the Very Large Array (VLA)
Synthetic radio image from the ANU simulation
An animation (requires Quicktime) of the simulated
explosion and development of the jets can be viewed here.
The simulations are carried out in a virtual cube (the box) that
represents a volume of space around the model galaxy. The cube is
divided into 16.8 million sub-cells, and the computer calculates
the flow of plasma in and out of each box as the explosion
evolves. These new models will be used to study the evolution
of radio galaxies, and the effect that the central black hole has
on the way stars form in their host galaxies.
For previous Monthly News items, click here.
Home
About Us
