Infrared and Submillimetre Observing Conditions on the Antarctic Plateau

Abstract

Abstract:The Antarctic Plateau provides the best terrestrial sites for infrared (IR) and submillimetre (sub-mm) astronomy. In this paper we examine the relative importance of temperature, aerosol content and precipitable water vapour to determine which parameters have the greatest influence on atmospheric transmission and sky brightness. We use the atmospheric modelling program MODTRAN to model the observed sky spectrum at the South Pole from the near-IR to the sub-mm. We find that temperature and aerosol content determine the quality of near-IR observing conditions, aerosol content is the determining factor in the mid-IR up to 20 µ m, while at longer wavelengths, including the sub-mm, it is the water vapour content that matters. Finding a location where aerosol levels are minimised is a key constraint in determining the optimum site on the Antarctic Plateau for an IR observatory.

Robotic telescopes on the Antarctic plateau

“…The sky at the South Pole is at least a factor of 10 lower in emission than Mauna Kea throughout the near and midinfrared (Smith and Harper 1998, Hidas et al 2000. At 2.35 m there is a natural gap between the airglow emission and the steeply rising thermal emission that leads to a factor of 100 improvement (Ashley et al 1996, Nguyen et al 1996, Phillips et al 1999.…”

Exoplanet spectroscopy from the Antarctic plateau

“…The proposed instrumental concept for APISD is a pair of fully automated, 60 cm telescopes located on fixed stations, operating in the λ = 2.8 − 4.2 µm range (extended L band), which corresponds to a transparency window at Dome C. 5 The distance between the two telescopes is established so as to provide adequate angular separation (λ/B = 1.5 mas at λ = 3.5 µm) for a B = 500 m baseline. The environment of Concordia provides an almost unlimited supply of flat real estate for very long baselines.…”

AMICA: the NIR/MIR camera for automatic astronomical observations from Dome C, Antarctica

“…Finally, at the high latitudes of the antarctic plateau, a large portion of the sky always remains above the horizon: this fact, combined with the excellent clearness of the sky and the possibility to observe also during daytime [7,13] , may allow a high duty cycle, perhaps 100% at λ > 4 μm . South Pole and Dome C [75 o 06 S, 123 o 23 E, 3250 m] have been the subject of intensive site testing campaigns [27,23,30] and are now recognized as excellent astronomical sites, especially in the infrared [24,43] , revealing themselves as exceptionally promising for the future installation of large telescopes [34] . These sites are not the unique to offer excellent observing conditions, however: new sites are opened to the interest of the world astronomical community.…”