far infrared
(FIR, far-IR)
(infrared radiation with wavelengths in the 30-450 μm range)
Far infrared (FIR) is electromagnetic radiation
at the opposite end of infrared from visible light.
The term is not consistently used, but often taken as EMR
with a wavelength between 15 μm and 1 mm.
In astronomy (far-infrared astronomy),
the term is typically used for the wavelength range is 30-450 μm.
It can indicate cold clouds of gas and dust,
cold matter of 140 kelvins or less.
The term submillimeter covers the range from 450 μm to 1 mm
and perhaps sometimes is used to cover far infrared astronomy as well.
The shorter-wavelength end of FIR has been somewhat observable
by infrared telescopes such as Spitzer Space Telescope, IRAS, and the
Infrared Space Observatory (all three defunct).
A few submillimeter telescopes reach the
very longest wavelengths, the Caltech Submillimeter Observatory (defunct) and the Atacama Large Millimeter Array (ALMA).
Telescopes covering the intervening range are scarce:
Herschel Space Observatory and SOFIA are both defunct
and very little observation can be carried out now.
All that remains is the 61-cm High Elevation Antarctic Terahertz Telescope in Antarctica
and some balloon-borne telescope projects.
(infrared,EMR,spectrum,band,submillimeter)
Further reading:
https://en.wikipedia.org/wiki/Far_infrared
https://en.wikipedia.org/wiki/Far-infrared_astronomy
https://en.wikipedia.org/wiki/Infrared_astronomy
https://www.icc.dur.ac.uk/~tt/Lectures/Galaxies/Images/Infrared/Regions/irregions.html
https://www.herschel.caltech.edu/page/far_infrared
http://spiff.rit.edu/classes/ast613/lectures/far_ir/far_ir.html
http://w0.ned.ipac.caltech.edu/level5/March14/Lutz/Lutz2.html
WaveL | Freq | Photon Energy | | |
30μm | 10THz | 41meV | begin | far infrared |
450μm | 666GHz | 2.8meV | end | far infrared |
|
Referenced by pages:
Atacama Desert
beat frequency
BLAST
bolometer
BOOMERanG
confusion limit
Cosmic Background Explorer (COBE)
emissivity
Fabry-Pérot interferometer (FPI)
Fred Young Submillimeter Telescope (FYST)
GUSTO
Herschel Space Observatory
High Elevation Antarctic Terahertz Telescope (HEAT)
hyperluminous infrared galaxy (HLIRG)
infrared (IR)
ionized carbon fine structure line ([CII])
IRTS
James Clerk Maxwell Telescope (JCMT)
luminous infrared galaxy (LIRG)
MAXIMA
multichroic feedhorn array
Origins Space Telescope (OST)
passband
PIXIE
Planck
PRIMA
RMS astronomy
SOFIA
SPICA
Submillimeter Telescope (SMT)
ultraluminous infrared galaxy (ULIRG)
Index