Astrophysics (index)about

integral field unit

(instrument to allow a spectrograph to capture data over a 2d field)

An integral field unit (IFU) is an instrument that allows a "normal" spectrograph, i.e., with a slit opening, to capture data across a two-dimensional field. The combined instrument is called an integral field spectrograph.

A typical spectrograph collects data from a line through an image (one dimension) and offers spectral data over one spatial dimension. The integral field unit rearranges points of light so that the slit includes data across a two-dimensional area, but at a relatively low spatial resolution. Spectrographs are often built so they can be used with or without the integral field unit.

Methods used:

An image slicer directs light from different parts of the image into a slit such that parts of the image across two dimensions are all fed through the one dimension of the slit width. UVES of the ESO VLT does this.

A lenslet array has a lens for each pixel. SAURON of the William Herschel Telescope (WHT) uses this.

Fibers uses optical fibers to direct the image into a single slit. INTEGRAL, another IFU for WHT, uses this.

The phrase IFU observation naturally refers to a spectrographic observation using an IFU.

(color,EMR,spectrum,instrument type)

Referenced by:
Anglo-Australian Telescope (AAT)
Giant Magellan Telescope (GMT)
imaging Fourier transform spectroscopy (IFTS)
imaging spectrometer
integral field spectrograph
multi-object spectrograph
William Herschel Telescope (WHT)