The Photodetector Array Camera and Spectrometer (PACS) on the Herschel Space Observatory
Lutz, D.; Altieri, B.; Andreani, P.; Cepa, J.; Genzel, R.; Poglitsch, A.; Popesso, P.; Sturm, E.; Okumura, K.; Rodriguez, L.; Henning, T.; Jean, C.; Sauvage, M.; Contursi, A.; Blommaert, J.; Krause, O.; Feuchtgruber, H.; Regibo, S.; Lemke, D.; Balog, Z.; Madden, S.; Benedettini, M.; Pezzuto, S.; Billot, N.; Ottensamer, R.; Klaas, U.; Kiss, C.; Boulade, O.; Müller, T.; Cesarsky, D.; Vandenbussche, B.; Waelkens, C.; Saraceno, P.; Orfei, R.; Doublier, V.; Geis, N.; de Jong, J.; Nielbock, M.; Schreiber, J.; Royer, P.; Vavrek, R.; Kerschbaum, F.; Morbidelli, L.; Barl, L.; Bauer, O. H.; Huygen, R.; Jakob, G.; Wiezorrek, E.; Wieprecht, E.; Duband, L.; Renotte, E.; De Meester, W.; Exter, K.; Doumayrou, E.; Martignac, J.; Tofani, G.; Grözinger, U.; Ali, B.; Jamar, C.; Katterloher, R.; Wetzstein, M.; Cara, C.; Schubert, J.; Gillis, J. -M.; Marquet, B.; van Hoof, C.; Agnèse, P.; Augueres, J. -L.; Belbachir, N.; Bischof, H.; Callut, E.; Cerulli, R.; Creten, Y.; Herreros, J.; Inguscio, M.; Mazy, A.; Merken, P.; Montfort, F.; Putzeys, J.; Reveret, V.; Stegmaier, J.; Schmitt, D.; Thiel, M.
Germany, Belgium, France, Italy, Spain, Austria, United States, Hungary
Abstract
The Photodetector Array Camera and Spectrometer (PACS) is one of the three science instruments on ESA's far infrared and submillimetre observatory. It employs two Ge:Ga photoconductor arrays (stressed and unstressed) with 16×25 pixels, each, and two filled silicon bolometer arrays with 16×32 and 32×64 pixels, respectively, to perform integral-field spectroscopy and imaging photometry in the 60-210 μm wavelength regime. In photometry mode, it simultaneously images two bands, 60-85 μm or 85-125 μm and 125-210 μm, over a field of view of ~1.75'× 3.5', with close to Nyquist beam sampling in each band. In spectroscopy mode, it images a field of 47” × 47”, resolved into 5×5 pixels, with an instantaneous spectral coverage of ~1500 km s-1 and a spectral resolution of ~175 km s-1. We summarise the design of the instrument, describe observing modes, calibration, and data analysis methods, and present our current assessment of the in-orbit performance of the instrument based on the performance verification tests. PACS is fully operational, and the achieved performance is close to or better than the pre-launch predictions.
Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.