Science Goals for Antarctic Infrared Telescopes
Michael G. Burton, John W.V. Storey, Michael C.B. Ashley, PASA, 18 (2), in press.
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Complementarity with other Facilities

A 2m Antarctic infrared telescope will provide a wide-field imaging facility with complementary functionality to the new generation of ground-based 8m telescopes and, further afield, to the next generation space facilities. These facilities are focussing on the thermal infrared as they probe deeper towards the `dark ages' of the Universe, and to the formation of stars and planets--processes whose detectable radiation lies in this waveband. While such facilities will be able to take extraordinarily deep images in the infrared, these will necessarily be of a narrow field of view. However, there is no equivalent of the optical Schmidt survey telescopes with which to guide these telescopes to interesting sources. The only substantive surveys at arcsecond resolution in the infrared are the DENIS (Fouqué et al. 2000) and 2MASS (Jarret et al. 2000) surveys, which only extend to K-band (2.2$\,\mu$m, for K< 14 mags.) in wavelength. A mid-IR survey in selected bands from 4-25 $\,\mu$m has been undertaken from space with the MSX satellite (Price et al. 1999), but with 18'' angular resolution (and limited sensitivity at 4$\,\mu$m). No facility has been built to conduct wide-field imaging in the 3-5$\,\mu$m and 8-14$\,\mu$m atmospheric windows at arcsecond resolution, a consequence of the limited sensitivities achieved in these bands from small telescopes at temperate sites. An Antarctic 2m will be able to fill this gap, providing the necessary capability at a small fraction of the cost of 8m and space facilities.

Such a telescope will therefore play a role in the scientific output not just of the new generation of ground-based 8m telescopes such as Gemini, but also in maximising the productivity of proposed space facilities such as NGST. An Antarctic 2m telescope can not only provide multi-wavelength wide-field surveys around sources of interest (to characterise, for example, the overall properties of a star forming cluster and the contamination from field stars), but also to select the obscured sources to be spectroscopically observed with NGST. The reddest sources in distant Galaxy clusters could be identified and serve as a finding list for NGST in the search and characterisation of proto-galaxies. Further afield, an Antarctic 2m telescope also provides an entry into the field of mid-IR interferometry, the focus of grand-design space programs such as Terrestrial Planet Finder (TPF) and Darwin. The combination of reduced sky background and improved stability over temperate sites means that the Antarctic plateau provides the best terrestrial location for a mid-IR interferometer, and therefore a proving ground to test the technology required for a spaced-based nulling interferometer.

The Douglas Mawson Telescope

We have proposed a 2m thermal infrared telescope for the Antarctic plateau, the Douglas Mawson Telescope. This is aimed at the science outlined in this paper, builds upon the scientific legacy and tradition that Australia has established in Antarctica, and provides a springboard for further involvement in major international facilities in the coming decades.

Douglas Mawson, the pioneering Australian Antarctic explorer and scientist, was also, in a sense, the first Antarctic astronomer. The first meteorite to be discovered in Antarctica was found on his expedition of 1912. Mawson realised both what it was, and the significance of the discovery for science. Mawson Station, Australia's first base on the Antarctic continent, was named after the explorer and established in 1954. The Douglas Mawson Telescope would establish Australia's first permanent facility on the high Antarctic plateau, where the bulk of the Australian Antarctic Territory lies.

The development of scientific facilities in Antarctica offers unique advantages for Australia. This arises from the proximity of the continent, the tradition of Antarctic science within Australia, and from the existence of the Australian Antarctic Territory. A new scientific station (Concordia Station) is now under construction at Dome C by France and Italy, a site which has possibily superior observing conditions to the Pole and which is within this Territory. Australia is in the process of establishing air links to the continent which will greatly facilitate access. The technology and capability to build and operate instruments in the harsh environment has been established over the past seven years through the site testing program at the South Pole, in particular by the AASTO (Automated Astrophysical Site Testing Observatory) program.

A 2m telescope has been chosen as the first intermediate-scale infrared facility to be developed, for a number of reasons. The size is large enough to be scientifically competitive, yet it is small enough to be relatively inexpensive. Instruments will also be small and therefore more readily fundable. The project does not need to challenge the technological envelope to succeed. A 2m telescope can be obtained commercially without needing to commission a specific design (although existing production models will need winterising). It can also be accomodated in a Hercules C130 aircraft for transportation. It will provide a versatile facility that can accomplish a wide-range of scientific projects. Finally, it can be readily expanded, through the provision of further 2m telescopes, to accomodate future developments and changes in direction.

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Contents Page: Volume 18, Number 2