The Cambridge Infrared Panoramic Survey Spectrograph was built at the Institute of Astronomy in Cambridge, UK. We warmly thank the Raymond and Beverly Sackler Foundation and PPARC for funding this project. We also wish to thank the Gemini Project for their support.
CIRPASS is a near-infrared (0.9 - 1.8 microns) fibre-fed spectrograph. Two fibre feeds exist: a 490 element integral field unit (IFU) and a 150 fibre multi-object bundle. The large spectrograph is operated inside a freezer working at -40 degrees celsius. The spectrograph camera, the filters and the detector are inside a dewar which is cooled by liquid nitrogen. Two image scales are available on the direct f/16 Gemini focus with eth IFU. The optics deliver a high resolution (R>3000) spectrum on to a mirror surface which is then reimaged on to the detector. This provides the option to block out, or suppress, the bright OH emission by making the mirror (or mask) non-reflective at the positions of the OH lines. Currently we are using plain mirrors and the OH is suppressed in software.
Our detector is a 1kx1k Hawaii-I HgCdTe array from Rockwell. We will upgrade to a 2kx2k Hawaii-II array sometime soon. This will give us twice the wavelength coverage in one hit. The number of fibres and hence the FOV and scale options will remain unchanged.