IRC: an infrared camera on board the IRIS

Basic design and current development status of IRC: an IR camera on-board the IRIS is presented. IRC is one of the focal-plane instruments of the 70cm cooled telescope of the IRIS. IRC utilizes recently developed large-format IR arrays for imaging and low-resolution spectroscopy at wavelength 1.8-26 micrometers . IRC consist of 3 camera channels: NIR, MIR-S, and MIR-L. These 3 channels simultaneously observe different fields of the sky, with diffraction-limited spatial resolution. One critical component limiting the performance of the IRC is the performance of large-format arrays: 512 X 412 format InSb and 256 X 256 format Si:As IBC arrays operation at very low temperature. Performance test of the Si:As array manufactured by the Hughes/SBRC is under way, and the preliminary results is presented. Design of the camera optics and the optical components is also presented. IRC is operated under the pointing observation of about 500 sec exposure time, and the development goal is to achieve high point-source detectivity limited nearly by the confusion due to faint astronomical sources.