Optics integration of the OMM wide-field visible camera (Panoramix-II)

Abstract

The advent of wide-field imagers on large telescopes (Megacam at CFHT, Suprime-Cam at Subaru, and others) with degree-wide fields of view is largely motivated by a renewed interest in our own solar system, in the history of the Milky Way and its neighbors, and in the large-scale structure of the Universe. Smaller, university-based telescopes can of course also benefit from wide-field imagery. We present in this paper the design and first results of Panoramix-II, the new wide-field imager of the Mont Megantic Observatory (OMM). This instrument is conceptually a focal reducer designed to image and correct the F/8 cassegrain focal plane of the telescope onto a pair of 2KX4K EEV detectors. The camera is optimized for the SLOAN g' (410-550 nm), r' (550-690 nm), i' (690-850 nm) and z' (850-950 nm) wave bands. The sky will be imaged onto the focal plane at an image scale of 0.52 arcsecond per 13.5 μm pixel. The design image quality is 1.00 arcsecond 50% diffraction encircled energy over the central 35 arcmin field and no images worse than 1.25 arcsecond over the 49 arcminute diameter camera field. The optical design distortion at the corners is less than 1%. The Panoramix-II camera has a filter wheel at the internal stop. Panoramix-II can also support the FaNTOmM photon-counting camera used in conjunction with a Fabry-Perot interferometer to provide spectrometric data.