FLAIR wide-field multi-object spectroscopy system

Although the 1.2-metre United Kingdom Schmidt Telescope (UKST) was built exclusively for the purpose of taking photographic plates, it became apparent in 1982 that the telescope's enormous field of view could be further exploited by carrying out multi-object spectroscopy using a floor-mounted long-slit spectrograph fed by low-loss optical fibres. In such an arrangement, the merits of the 40 deg² field could be combined with those of the most sensitive electronic detectors to offer the promise of large-scale intermediate-dispersion spectroscopic surveys for objects brighter than about 18th magnitude, a task not practicable on conventional telescopes even of considerably larger aperture. To this end, a multi-object feed system known as the Fibre-Linked Array-Image Reformatter (FLAIR) has been developed for the UKST. An early prototype, completed in 1985, was substantially improved in 1988 and now provides an effective and unique wide-field CCD spectroscopy service on a common-user basis. Target objects are typically galaxies with B ≤ to 17.5 for redshift determination, but stars, too are commonly observed. A feature of the spectra is their very high wavelength stability. Time-resolved multi-object photometry of variable objects has also been successfully carried out. Work has recently begun on a second-generation system, FLAIR II. With improved front-end arrangements and a new spectrograph, FLAIR II is expected to produce further substantial gains in efficiency and performance.