A 3 degree prime focus field for the AAT

摘要

The Anglo-Australian Telescope's 2° field 400 fiber prime focus feed for spectroscopy has been very successful. For anew instrument proposal (known as Hector) to provide robotically deployed IFUs at the AAT prime focus, a correctorgiving a field 3° in diameter is required to make optimum use of as many as 100 IFUs. Having IFUs with individualfield diameters of 10 to 15 arcsec feeding spectrographs allows some relaxation in the tolerances to lateral chromaticaberration and to atmospheric dispersion, since each can be compensated computationally without much loss inefficiency. The AAT has four removable top ends, of which the original prime focus version could be recycled to carry amuch larger corrector. Its outer ring passes a field up to 3.3° diameter without vignetting and the dome slit has a littlemore clearance. A very satisfactory optical design has been developed for a corrector providing 3° field diameterwithout vignetting, having six elements with three non-spherical surfaces. The diameter of the largest element is 1250mm. The corrector also works well for direct imaging on a flat field up to 1° diameter.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.