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Herschel Science Instruments
The Herschel science payload comprises three instruments which have been conceived and optimised with the prime science goals in mind. The instruments offer a wide range of capabilities to cater for a wide and diverse range of observing programs. The instruments were selected from the response to an Announcement of Opportunity (AO) issued in October 1997.
The Principal Investigators (PIs) and the instruments selected were:
The PI consortia provide the instruments to ESA under their own funding, in return for guaranteed observing time. The science instruments were selected by the ESA Science Programme Committee in May 1998 and finally approved in February 1999.
PACS is a camera and low to medium resolution spectrometer for wavelengths in the range 55-210 µm. It employs four detector arrays, two bolometer arrays and two Ge:Ga photoconductor arrays. The bolometer arrays are dedicated for wideband photometry, while the photoconductor arrays are to be employed exclusively for spectroscopy with a resolution of a few thousand. PACS can be operated either as an imaging photometer, or as an integral field line spectrometer.
SPIRE is a camera and low to medium resolution spectrometer complementing PACS for wavelengths in the range 194-672 µm. It comprises an imaging photometer and a Fourier Transform Spectrometer (FTS), both of which use bolometer detector arrays. There are a total of five arrays, three dedicated for photometry and two for spectroscopy.
HIFI is a very high resolution heterodyne spectrometer covering the 490-1250 GHz and 1410-1910 GHz bands. It utilises low noise detection using superconductor-insulator-superconductor (SIS) and hot electron bolometer (HEB) mixers, together with acousto-optical and autocorrelation spectrometers. HIFI is not an imaging instrument, it observes a single pixel on the sky at a time.
Instrument detailed information
Detailed information is available describing the use of the Herschel observatory and its instruments in the form observers' manuals, observing planning tools, and presentations provided in various workshops.
See Useful links