Molonglo Observatory Synthesis Telescope
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The Molonglo Observatory Synthesis Telescope (MOST) is a radio telescope operating at 843 MHz. It is operated by the School of Physics of the University of Sydney. The telescope is located near the Molonglo River near Canberra, Australian Capital Territory, and was constructed by modification of the East-West arm of the former Molonglo Cross Telescope, a larger version of the Mills Cross Telescope.
The MOST consists of two cylindrical paraboloids, 778m x 12m, separated by 15m and aligned East-West. A line feed system of 7744 circular dipoles collects the signal and feeds 176 preamplifiers and 88 IF amplifiers. The telescope is steered by mechanical rotation of the cylindrical paraboloids about their long axis, and by phasing the feed elements along the arms. The resulting `alt-alt' system can follow a field for +/- 6 hours (necessary for a complete aperture synthesis with an East-West array) only if the field is south of declination -30 degrees. For fields near this limit the signal-to-noise ratio is lower for the first and last hour or so due to the lower gain of the system at large 'meridian distance' angles.
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[edit] Molonglo Cross Telescope
The Molonglo Cross Telescope was a 408 MHz radio telescope built by Bernard Y. Mills and collaborators and operated by the University of Sydney. The telescope consisted of a North-South arm and an East-West arm in a cross shape. Each arm was approximately one mile in length. It was used for a survey of the Southern sky with a resolution of 2.8 arcmin. Much pioneering radio astronomy was done with this telescope. The East-West arm was split into 88 individual elements to form the current Molonglo Observatory Synthesis Telescope.
[edit] MOST Current work
Currently, the telescope's main research project is the Sydney University Molonglo Sky Survey (SUMSS), a sensitive radio imaging survey of the southern sky at 843 MHz with similar resolution and sensitivity to the northern NRAO VLA Sky Survey (NVSS). SUMSS is now almost complete, and digital images and a source catalogue are available online.[1]
[edit] Square Kilometer Array development
MOST is being used to develop technology for the Australian candidate site of the Square Kilometer Array telescope. Since 2003 work has proceeded on the SKA Molonglo Prototype (SKAMP) which has included fitting new wide-band feeds, low-noise amplifiers, digital filterbanks and correlator, in order to demonstrate 300-1420 MHz continuous frequency coverage and multibeam mode operation. The new correlator is a 96 input continuum correlator using Field Programmable Gate Array (FPGA) chips.[2]
This effort is a collaboration between the Australia Telescope National Facility (ATNF), the Australian Commonwealth Scientific and Industrial Research Organisation (CSIRO) Information and Communications Technology Centre, and the University of Sydney.
[edit] Notes
- ^ Sydney University Molonglo Sky Survey Home Page. Astrophysics Research Group:. University of Sydney. Retrieved on 2007-01-30.
- ^ The SKA Molonglo Prototype (SKAMP) - Prototyping SKA Technologies at the Molonglo Radio Telescope. Institute of Astronomy. University of Sydney (2003). Retrieved on 2007-01-30.
[edit] References
- Molonglo Observatory Synthesis Telescope. Institute of Astronomy. University of Sydney (2003). Retrieved on 2007-01-30.
