摘要
The Antarctic plateau provides some exciting possibilities for astronomical observations. The next decade may see a significant astronomical buildup on the Antarctic Plateau. Dome A and Dome C are currently the two most promising sites. These high points on the plateau have unique properties for astronomical observations. Two of these arise from the extreme cold: the column density of water vapor is lower than at any other site, thus opening unique windows at infrared and submillimeter wavelengths; and the ambient temperature, and thus the thermal background emission of telescope mirrors, is lower than at any other site. Two more advantages arise from the unique character of the atmospheric turbulence: the atmospheric boundary layer is extremely thin, only tens of meters, which opens the possibility of wide field, high resolution imaging by either adaptive correction of the thin ground layer or by raising the telescope above the boundary layer; the wind speeds at all levels of the atmosphere are low, which is highly favorable for adaptive
correction. It will likely be possible to form diffraction limited images over a good fraction of the sky down to visible light wavelengths three times HST resolution for an 8 m telescope. Dome A, being the highest and coldest point in Antarctica, is especially promising based on the results of recent theoretical models and site surveys. More comprehensive site monitoring should be planned for the next decade. Based on existing data, the site has certain areas of astronomical observations can already be planned with little risks. Wide field near-IR imaging, for example, relies critically on the thermal background and the low temperature at Dome A makes it an ideal site. Another key area is likely to be exoplanet imaging and spectroscopy in the L-band, where the combination of
super-diffraction limited AO correction and the very low thermal background will enable very high contrast imaging at very close inner working angle, for example 0.15 arcsec for an 8 m telescope.
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