Integral Field Spectroscopy
Integral field spectroscopy (IFS) is a mode of instrumentation that enables spectra to be obtained of a 2-dimensional region of the sky.
From IFS observations a "data cube" is generated, which is essentially a stack of many images of the same part of the sky, each at a different wavelength. Such data enable ground-breaking discoveries about the motions and makeup of gas and stars in extended sources, such as gas clouds or dense star-clusters in the Milky Way, regions around active galactic nuclei, and even entire galaxies.
Conventional spectrometers or spectrographs have entrance apertures that sample a single point, or a long line (slit) on the sky. By using fiber-optics or relay optics, it is possible to remap a two-dimensional region on the sky into the long slit of a conventional spectrograph. UW astronomers have developed unique integral field units (IFUs) to convert conventional long-slit spectrographs into engines for IFS, including the SparsePak IFU for the Bench Spectrograph on the WIYN 3.5m.