The Photoconductor Array Camera & Spectrometer (PACS) for the Far Infrared and Submillimetre Telescope (FIRST)

The Photoconductor Array Camera & Spectrometer (PACS) is one of the three science instruments for ESA's Far Infra-Red and Submillimetre Telescope (FIRST). It employs two 16 x 25 pixels Ge:Ga photoconductor arrays (stressed/unstressed) to perform imaging photometry and imaging line spectroscopy in the 60 - 210 mu m wavelength band, with an optional extentions to similar to 300 mu m. In photometry mode, it will simultaneously image two bands, 60 - 90 or 90 - 130 mu m and 130 - 210 mu m, over fields of view of similar to 1' x 1.5' and similar to 2' x 3', respectively, with full beam sampling in each band. In spectroscopy mode, it will image a field of similar to 50 " x 50 ", resolved into 5 x 5 pixels, with an instantaneous spectral coverage of similar to 1500km/s and a spectral resolution of similar to 175km/s. In both modes background-noise limited peformance is expected, with sensitivities (5 sigma in Ih) of 4 - 6 mJy or 3 x 10(-18)W/m(2) respectively.