Astronomy with an imaging Fourier-transform spectrometer

A 3-D spectrometer is a particularly useful instrument in astronomy where many sources are extended objects or star clusters. With the advent of bidimensional array detectors the throughput advantage of a Fourier-transform spectrometer (FTS) can be exploited to create this type of instrument. The coupling of the FTS of the CFH Telescope, which is a step-scan interferometer, to a near-infrared camera has been realised. With this combination, spectro-imaging in any bandpass between 1 and 2.5 μm is possible within a circular 24” field of view, at seeing-limited spatial resolution. Spectral resolution in any spectral domain within these limits, up to 30,000 is choosable. Illustrations are given by the study of several typical objects.