The Herschel-SPIRE instrument

摘要

SPIRE, the Spectral and Photometric Imaging Receiver, is one of three scientific instruments which will fly on the European Space Agency's Herschel Space Observatory. SPIRE contains two sub-instruments: a three-band imaging photometer operating at 250, 360 and 520 microns, and an imaging Fourier Transform Spectrometer (FTS) covering 200-670 microns. The detectors are arrays of feedhorn-coupled NTD spider-web bolometers cooled to 300 mK. The photometer field of view of is 4 x 8 arcminutes, observed simultaneously in the three spectral bands. An internal beam steering mirror allows spatial modulation of the telescope beam and will be used to jiggle the field of view in order to produce fully-sampled images. Observations can also be made by scanning the telescope without chopping. The FTS has an approximately circular field of view with a diameter of 2.6 arcminutes, and employs a dual-beam configuration with broad-band intensity beam dividers to provide high efficiency and separated output and input ports. The spectral resolution can be adjusted between 0.04 and 2 cm-1 (λ/Δλ = 20 - 1000 at 250 microns). The instrument design, operating modes, and estimated sensitivity are described, and the current status of the project is reported.