UNSWIRF - A TUNABLE IMAGING SPECTROMETER FOR THE NEAR-INFRARED

We describe the specifications, characteristics, calibration, and anal ysis of data from the University of New South Wales Infrared Fabry-Per ot (UNSWIRF) etalon. UNSWIRF is a.near-infrared tunable imaging spectr ometer, used primarily in conjunction with IRIS on the AAT, but suitab le for use as a visitor instrument at other telescopes. The etalon del ivers a resolving power in excess of 4000 (corresponding to a velocity resolution similar to 75 km s(-1)), and allows imaging of fields up t o 100 '' in diameter on the AAT at any wavelength between 1.5 and 2.4 mu m for which suitable blocking filters are available.