New filters for NIR-MIR astronomy from Dome C: the case of AMICA

Abstract

Dome C, located on the Antarctic Plateau, is expected to be one of the best sites for ground-based astronomical observations at infrared wavelengths. Its high elevation, equivalent to 3800 m of a temperate site, and the very low temperatures (down to -90°C), reduce dramatically the background thermal emission from both the instrument and the sky; the very dry and cold environment makes the atmospheric windows more transparent, wide and stable than in any ground-based temperate site. The Antarctic Multiband Infrared Camera (AMICA), mounted at the focal plane of the IRAIT telescope, is designed to perform astronomical observations at near- and mid-infrared wavelengths from Dome C. In order to fully exploit the above-mentioned excellent site conditions, a set of optimized infrared filters covering the 2 - 25 microns region has been defined as a result of a careful analysis. In the first step, the bands of interest were identified on the basis of the scientific requirements and the opportunities offered by the site. The fundamental scientific parameters, as the central wavelength, the bandwidth, the isophotal magnitude were then computed for each filter, in such a way to optimize the camera performances.