integral field unit
(IFU)
(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.
Among the IFU mechanisms used:
- An image slicer uses mirrors arranged to separately reflect slices of the image, placing the slices end-to-end along the length of the slit. UVES of the ESO VLT does this.
- A lenslet array has a 2-dimensional array of lenses, that direct light from the image to sections along the length of the slit. SAURON, formerly of the William Herschel Telescope (WHT) used this.
- Fibers uses optical fibers, arranged in a 2-dimensional array to pick up pixels of the image, outputting these pieces of the image along the length of the slit. INTEGRAL, another IFU formerly of the WHT, used this.
The phrases IFU observation and IFU spectroscopy naturally refer to a
spectrographic observation using an IFU.
(color,EMR,spectrum,instrument type)
Further reading:
https://en.wikipedia.org/wiki/Integral_field_spectrograph
http://www.ucolick.org/~bolte/AY257/ay257_5a.pdf
http://www.astro.caltech.edu/~george/ay122/Ay122a_Spectroscopy.pdf
https://www.eso.org/public/teles-instr/technology/ifu/
https://www.sdss.org/dr13/manga/manga-tutorials/what-is-ifu-spectroscopy/
https://www.astro.wisc.edu/?page_id=658
http://ifs.wikidot.com/
Referenced by pages:
Anglo-Australian Telescope (AAT)
ATHENA
European Extremely Large Telescope (E-ELT)
European Southern Observatory Very Large Telescope (ESO VLT)
Giant Magellan Telescope (GMT)
HARMONI
imaging Fourier transform spectroscopy (IFTS)
imaging spectrometer
integral field spectrograph
IRTF
James Webb Space Telescope (JWST)
NIRSpec
PHANGS
Sloan Digital Sky Survey (SDSS)
spectroscopy
William Herschel Telescope (WHT)
WIYN 3.5m Telescope
Index