Mid-Infrared Instrument

Technical Info

For detailed instrument information, please consult the MIRI JWST User Documentation (JDox)

Simulated MIRI MRS observation
Simulated MIRI MRS observation illustrating an uncalibrated detector image (upper left panel) and the corresponding three-dimensional data cube (upper right panel) and extracted one-dimensional spectrum (lower panel).

The Mid-Infrared Instrument (MIRI) provides JWST observers with coverage of mid-infrared wavelengths from 4.9 to 28.8 μm. Imaging can be obtained with 9 broad-band filters covering the wavelength ranges from 5.6µm to 25.5µm. Spectroscopy can be obtained with a low spectral resolving power mode from 5-12µm that includes both slitted and slitless options, or with a medium spectral resolving power integral field unit from 4.9µm-28.8µm. MIRI also contains one Lyot and three 4-quadrant phase mask coronagraphs that are optimized to the mid-infrared spectral region.

MIRI was developed through a collaboration between the European Consortium and the Jet Propulsion Laboratory (JPL). The European MIRI Principal Investigator is Gillian Wright (UK Astronomy Technology Centre), and the U.S. Principal Investigator is George Rieke (University of Arizona). The MIRI Instrument Scientists are Alistair Glasse at UKATC and Michael Ressler at JPL.

Additional Resources:

MIRI-related news


MIRI at University of Arizona

Royal Observatory Edinburgh

Near-Infrared Camera

Technical Info

For detailed instrument information, please consult the NIRCam JWST User Documentation (JDox).

NIRCam imaging
NIRCam imaging covers the two adjacent fields of total area 9.7 arcmin². Long and short wavelengths are observed simultaneously. Because of the changing size of the PSF, the short wavelengths use four detectors in each module while the long wavelengths are covered by one detector.

The Near-Infrared Camera (NIRCam) is JWST’s primary imager in the wavelength range from 0.6 to 5 μm. It consists of two, nearly identical, fully redundant modules, which point to adjacent fields of view on the sky and can be used simultaneously.  Each module uses a dichroic to also observe simultaneously in both the short wavelength channel (0.6–2.3 μm) and long wavelength channel (2.4–5.0 μm).  

In addition to imaging with a wide range of narrow, medium, and broad filters, NIRCam also offers wide field slitless (grism) spectroscopy and coronagraphic imaging modes, as well as time-series and grism time-series observing modes for high accuracy photometric monitoring and spectrophotometric monitoring, respectively.   NIRCam also obtains wavefront  sensing measurements critical for periodic alignment and phasing of the segments of JWST's primary mirror.

NIRCam was built by a team at the University of Arizona and Lockheed Martin’s Advanced Technology Center, led by Principal Investigator Marcia Rieke from the University of Arizona.

Additional Resources:

NIRCam-related news


NIRCam at the University of Arizon

Near-Infrared Imager and Slitless Spectrograph

Technical Info

For detailed instrument information, please consult the NIRISS JWST User Documentation (JDox).

Illustration showing various simulated NIRISS images.
NIRISS Wide-Field Slitless Spectroscopy simulations of the gravitationally lensed cluster MACS J0416.1-2403. Left: Image through the F200W filter. Middle and right: Slitless spectra through the F200W filter with the GR150R grism and the GR150C grism. Observations with orthogonal dispersion directions can be used to disentangle blended spectra in crowded fields.

The JWST Near-Infrared Imager and Slitless Spectrograph (NIRISS) provides unique observational capabilities between 0.6 and 5 microns that complement those available with NIRCam and NIRSpec. Its efficient, all-reflective design enables low-resolution, wide-field grism spectroscopy; medium-resolution grism spectroscopy optimized for applications  requiring extreme spectrophotometric stability; aperture masking interferometry; and parallel imaging through filters matched to those available with NIRCam.

NIRISS is a contribution of the Canadian Space Agency to the JWST project.  Honeywell International designed and built the instrument in collaboration with a team lead by the Principal Investigator, René Doyon of the Université de Montréal. Additional technical support was provided by the National Research Council of Canada’s Herzberg Astronomy and Astrophysics Research Centre.

Additional Resources:

NIRISS-related news

Canadian Space Agency


Near-Infrared Spectrograph

Technical Info

For detailed instrument information, please consult the NIRSpec JWST User Documentation (JDox).

An example of NIRSpec MOS mode spectra
An example of NIRSpec MOS mode spectra taken with a calibration flat field lamp, providing uniform illumination, and example MSA shutter slitlets using the G140M+F100LP spectral configuration. 

JWST's Near-Infrared Spectrograph (NIRSpec) is a versatile spectroscopic instrument that operates in the 0.6 to 5.3 μm wavelength range.  NIRSpec offers high throughput single object spectroscopy through fixed slits, spatially-resolved integral field unit spectroscopy, and a powerful multi-object spectroscopic mode using a micro-shutter assembly.  NIRSpec also has a bright object time series mode through a wide aperture that provides high throughput/high accuracy spectrophotometric monitoring capabilities to the astronomical community.

NIRSpec was built for the European Space Agency by Airbus Industries with the Micro-Shutter Array (MSA) and detector sub-systems fabricated by NASA. Pierre Ferruit is the NIRSpec Principal Investigator.

Additional Resources:

NIRSpec-related news

NIRSpec at ESA



Science Resources

Data Simulations

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Technical Documents

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For technical assistance, please contact the JWST Help Desk.

The NASA James Webb Space Telescope, developed in partnership with ESA and CSA, is operated by AURA’s Space Telescope Science Institute.

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