Instrumentation

Australian organisations are fast developing an international reputation for building and designing quality radio receivers and telescope instrumentation. Such is the expertise within the country, there is much demand for external contracts by international organisations.

Antarctic Astronomy:

The thin, dry and cold air on the high Antarctic plateau combined with stable weather conditions and the six month Antarctic night make it Earth’s premier observing site. The ambient environment confers special advantages at infrared and millimetre wavelengths, where the intense cold diminishes the thermal IR background and the lack of water vapour in the atmosphere significantly improves the atmospheric transmission in the millimetre. However, there are many technical, logistical and human challenges to overcome before building an observatory in this remote and inhospitable landscape. In many ways placing and observatory in Antarctica is akin to building a space observatory with all the same advantages but at a fraction of the cost.

Since 1997 ANU and UNSW in conjunction with JACARA, have maintained a little piece of Australia at the South pole. The Automated Astrophysical Site Testing Observatory (ASSTO) is a self-contained observatory designed to operate automatically for periods of up to a year without any human supervision. Its ongoing mission is to conduct a range of site testing experiments to asses the feasibility of installing a large 2m class telescope on the high Antarctic plateau. With two years of site testing completed, the next bold step is to relocate the ASSTO 2000km to the high point ‘Dome C‘, the most promising site for a future observatory. Follow the progress of the Antarctic team in summer 2002/2003 on the UNSW South Pole diaries site. Updates are made daily.

Echidna:

Echidna is a multifibre feed of radical new design being developed by the Australian Astronomical Observatory for the FMOS spectrograph on Japan’s Subaru Telescope. Rather than being placed by a robot, each fibre is mounted on its own independently moveable spine, controlled by a piezoelectric actuator: this allows the fibres to be packed much more closely together. Echidna will position up to 400 fibres in a 30 arcminute diameter field of view at the telescope’s prime focus.

GSAOI – Australia’s second Gemini Instrument:

The ANU’s Research School of Astronomy and Astrophysics also won the tender to build the Gemini South Adaptive Optics Imager (GSAOI), which is a special camera for the Gemini South Telescope in Chile. Gemini South will be fitted with a special adaptive optics system, which compensates for the way light is distorted as it passes through the Earth’s atmosphere, resulting in infrared pictures that will be as sharp as pictures from the Hubble Space Telescope. GSAOI and Gemini South’s adaptive optics system will allow astronomers to study in detail how, when and where stars formed in nearby galaxies, as well as study how galaxies have evolved over the history of the Universe.

HERMES:

HERMES will be the next major instrument for the 3.9-m Anglo-Australian Telescope (AAT), and is currently under construction at AAO. The HERMES system is built upon the AAT’s existing two-degree field (2dF) optical fibre positioner, which can collect the light from 400 stars at a time. The positioner feeds a powerful new spectrograph which covers four optical bands simultaneously at a spectral resolution of ~28,000. The primary HERMES science project is the “Galactic Archaeology” (GA) Survey, which aims to reconstruct the history of our Galaxy’s formation from precise multi-element abundances of 1 million stars derived from HERMES spectra. This survey is being prepared and will be handled by the GA Survey Team.

LOFAR:

LOFAR (Low Frequency Array) is the first of the next-generation radio telescopes based on geographically distributed, but connected, systems of array-stations. LOFAR is being designed to operate at frequencies from approximately 10 – 250 MHz. In many respects LOFAR is a low-frequency prototype version of the SKA, and is a direct developmental step towards the SKA. LOFAR is expected to start initial operations around the time of the next solar minimum in 2006 – 2008, with an estimated cost of A$200M.

A site in inland Western Australia is one of three sites around the world shortlisted as the site for LOFAR. The advantages of the Australian site include superb radio-quiet, a Southern Hemisphere location, optimised infrastructure and excellent land accessibility leading to optimum placement of array-stations. A decision on the location of a site for LOFAR is expected by the end of 2003.

The current LOFAR Consortium members are the US Naval Research Laboratory, the Massachusetts Institute of Technology Haystack Observatory, and the Netherlands Foundation for Research in Astronomy (ASTRON). During February 2-9, 2003, a delegation from the LOFAR consortium visited Australia to discuss possible collaborations and Australian involvement in LOFAR with Australian scientists, engineers, policy managers and government advisers, at both State and Federal levels. They also visited the potential LOFAR site in Western Australia and discussed siting issues with the Western Australian Government.

Millimetre-wave upgrade for the Australia Telescope:

New cutting-edge receivers have made CSIRO’s Australia Telescope Compact Array the first millimetre-wave synthesis telescope in the Southern Hemisphere, enabling astronomers to observe the richest part of the Galactic Plane and the nearest star-forming galaxies, the Magellanic Clouds, in unprecedented detail.

All six of the Compact Array antennas have been outfitted with receivers working at 12-mm wavelengths. By 2004 five of them will also be outfitted with receivers for 3-mm operation. With its 22-m dishes, the ATCA will then be the world’s largest millimetre-wave interferometer in terms of collecting area.

At the heart of the receivers is a new chip made of the exotic material indium phosphide, cryogenically cooled to 20 K (-253 C) for operation. The chips were designed by CSIRO engineers and fabricated by Velocium, a telecommunication products company of US firm TRW (now Northrop Grumman).

The upgrading of the Australia Telescope to work at millimetre wavelengths has been funded by the Federal Government under its Major National Research Facilities (MNRF) Program, and by CSIRO.

PASA review paper
Millimetre Science with the Upgraded Australia Telescope

MNRF Funding:

In 2001, the Federal Government awarded the Australian astronomical community A$23.5 million over five years, through the Major National Research Facilities (MNRF) program. The funding will be used to develop new technology for the international next-generation radio telescope, the Square Kilometre Array, and to increase Australia’s share in the Gemini consortium.

NIFS – Australia’s first Gemini Instrument:

The Research School of Astronomy and Astrophysics at ANU was contracted by the Gemini Partnership to build the Near-infrared Integral Field Spectrograph or NIFS. Combined with Gemini North’s adaptive optics system, known as ALTAIR, the instrument is capable of studying the northern sky in the near-infrared on scales comparable to the Hubble Space Telescope in the optical. NIFS was designed with the following specific science goals in mind: To study massive black holes in galactic nuclei, the excitation of inner narrow-line regions of Seyfert galaxies and dynamic galactic evolution. For detailed description of science with NIFS see the PASA review paper below.

PASA Review Paper:
Science with NIFS, Australia’s first Gemini Instrument

Optical Interferometry:

Long baseline interferometry has been a major research effort at the University of Sydney for 40 years, with the Sydney University Stellar Interferometer (SUSI) now the longest baseline instrument in the world. Masked-aperture interferometry on conventional large optical telescopes is also explored. Research has included the MAPPIT project at 3.9-metre AAT and more recent work using the 10-metre Keck telescopes.

Parkes Multibeam Receiver:

The 21cm Multibeam Receiver is a facility available on the Parkes Telescope which is operated by the Australia Telescope National Facility (ATNF), CSIRO. The facility consists of a 13-beam cooled 21cm receiver system, located at the prime focus of the 64m dish. The hexagonal feed cluster was designed by the CSIRO Division of Telecommunications and Industrial Physics. The receiver was built as a collaboration between: the ATNF receiver group; the Universities of Melbourne, Sydney and Cardiff; Mount Stromlo and Siding Spring Observatories; and Jodrell Bank with funding provided by the ARC and the ATNF.

Two complementary surveys of extragalactic HI have been carried out on the Multibeam Receiver at Parkes– the HIPASS survey and the Zone of Avoidance (ZOA) survey. HIPASS data tracing the large-scale arrangement of galaxies in the southern sky is now publicly available to the astronomical community.

Data Archive: HIPASS data
Research Papers: HIPASS papers

Robotic fibre-positioners:

In the last decade the Australian Astronomical Observatory has designed and built three outstanding robotic fibre-positioners: the 2dF (two-degree field) and 6dF (six-degree field) systems for its own telescopes, and OzPoz for ESO’s VLT.

The 2dF system, used on the 3.9-m AAT, allows up to 400 spectra of objects to be acquired simultaneously within a two-degree field. The instrument consists of a wide-field corrector, an atmospheric dispersion compensator, a robot gantry that positions optical fibres to 0.3”, and two spectrographs, each of which accepts 200 of the fibres to produce low to medium resolution spectra. A tumbling mechanism with two field plates allows one field to be configured while another is being observed. Two major redshift surveys carried out with the instrument, the 2dF Galaxy Redshift Survey and the 2dF QSO Redshift Survey, were completed in 2002: they netted the redshifts of 221,000 galaxies and 23,000 quasars respectively. The unprecedented size of the surveys allowed them to capture the Universe’s structure on scales of up to 1000 million light-years, which had previously been impossible.

The 2dF instrument’s successor on the AAT will be AAOmega. This instrument will use some existing 2dF infrastructure but will also include new features, such as a Dual Beam Schmidt Spectrograph allowing simultaneous red and blue observations with large-format detectors.

The 150-fibre 6dF instrument, similar to 2dF, was built for the AAO’s 1.2-m UK Schmidt telescope. 6dF’s principal task during 2001-2004 is to carry out an all-southern-sky galaxy redshift and peculiar-velocity survey. However, a ten-country consortium has just begun to use the instrument for the RAVE (radial velocity) survey – the largest-ever spectroscopic survey for stellar radial velocities, collecting up to 600 spectra a night. By 2005 the RAVE team plans to have 100,000 spectra – five times as many as have been measured over the last 125 years.

OzPoz is a multifibre positioner developed by the AAO for ESO, to feed Nasmyth spectrographs on VLT UT2. The A$3.5M instrument was commissioned in 2002, and was Australia’s first major contract with ESO. OzPoz follows the same basic concept as 2dF but has some novel features, such as a pneumatically operated gripper using air bearings.

Starbugs is a versatile parallel fibre-positioning technology that is being developed by the AAO. Starbugs is an enabling technology proposed for the MANIFEST (many instrument fibre system) concept for the Giant Magellan Telescope. Starbugs prototypes have been developed as part of the MANIFEST feasibility study during 2010/11.

PASA papers:
The 2dF Gravitational Lens Survey
Radio Sources in the 2dF Galaxy Redshift Survey. I. Radio source populations

SkyMapper:

The SkyMapper telescope under construction by ANU’s Research School of Astronomy and Astrophysics and Electro Optic Systems Australia will be the first of a new breed of survey telescopes able to scan the night skies more quickly and deeper than ever before. The telescope will scan 5 square degrees with each image – five times faster than any existing large telescope. The resulting Stromlo Southern Sky Survey will be the first comprehensive digital map of the Southern sky.

Square Kilometre Array:

Australia is developing technology for the world’s next generation radio telescope, the Square Kilometre Array or SKA. The SKA will have a collecting area of one square kilometre (one million square metres) – about 100 times as great as that of the biggest present-day radio telescopes. Twelve countries are working together on this ambitious project.

A formal Australian SKA Consortium was established in 2001. Australian research institutions currently involved with the SKA project include CSIRO, the University of Sydney, the Australian National University and Swinburne University of Technology.

During 2002-07 Australia will spend about A$20 million on SKA R&D: much of this funding was provided by the Commonwealth Government under the Major National Research Facilities program. Two technology demonstrators will be completed in time for evaluation by the international SKA community Australia Telescope Compact Array at Narrabri, the other will use the University of Sydney in the period 2005-2007. One will be based around the Molonglo Observatory Synthesis Telescope. The MNRF program will also allow Swinburne University to undertake advanced system simulations needed for the SKA design process.

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