The Near Infrared Imager and Slitless Spectrograph for the James Webb Space Telescope. I. Instrument Overview and In-flight Performance

Doyon, René, Chris J. Willott, John B. Hutchings, Anand Sivaramakrishnan, Loïc Albert, David Lafrenière, Neil Rowlands, M. Begoña Vila, André R. Martel, Stephanie LaMassa, David Aldridge, Étienne Artigau, Peter Cameron, Pierre Chayer, Neil J. Cook, Rachel A. Cooper, Antoine Darveau-Bernier, Jean Dupuis, Colin Earnshaw, Néstor EspinozaJoseph C. Filippazzo, Alexander W. Fullerton, Daniel Gaudreau, Roman Gawlik, Paul Goudfrooij, Craig Haley, Jens Kammerer, David Kendall, Scott D. Lambros, Luminita Ilinca Ignat, Michael Maszkiewicz, Ashley McColgan, Takahiro Morishita, Nathalie N.Q. Ouellette, Camilla Pacifici, Natasha Philippi, Michael Radica, Swara Ravindranath, Jason Rowe, Arpita Roy, Niladri Roy, Karl Saad, Sangmo Tony Sohn, Geert Jan Talens, Driss Touahri, Deepashri Thatte, Joanna M. Taylor, Thomas Vandal, Kevin Volk, Michel Wander, Gerald Warner, Sheng Hai Zheng, Julia Zhou, Roberto Abraham, Mathilde Beaulieu, Björn Benneke, Laura Ferrarese, Ray Jayawardhana, Doug Johnstone, Lisa Kaltenegger, Michael R. Meyer, Judy L. Pipher, Julien Rameau, Marcia Rieke, Salma Salhi, Marcin Sawicki

Research output: Contribution to journalArticlepeer-review

6 Scopus citations


The Near-Infrared Imager and Slitless Spectrograph (NIRISS) is the science module of the Canadian-built Fine Guidance Sensor onboard the James Webb Space Telescope (JWST). NIRISS has four observing modes: (1) broadband imaging featuring seven of the eight NIRCam broadband filters, (2) wide-field slitless spectroscopy at a resolving power of ∼150 between 0.8 and 2.2 μm, (3) single-object cross-dispersed slitless spectroscopy (SOSS) enabling simultaneous wavelength coverage between 0.6 and 2.8 μm at R ∼ 700, a mode optimized for exoplanet spectroscopy of relatively bright (J < 6.3) stars and (4) aperture masking interferometry (AMI) between 2.8 and 4.8 μm enabling high-contrast (∼10−3 − 10−4) imaging at angular separations between 70 and 400 mas for relatively bright (M < 8) sources. This paper presents an overview of the NIRISS instrument, its design, its scientific capabilities, and a summary of in-flight performance. NIRISS shows significantly better response shortward of ∼2.5 μm resulting in 10%-40% sensitivity improvement for broadband and low-resolution spectroscopy compared to pre-flight predictions. Two time-series observations performed during instrument commissioning in the SOSS mode yield very stable spectro-photometry performance within ∼10% of the expected noise. The first space-based companion detection of the tight binary star AB Dor AC through AMI was demonstrated.

Original languageEnglish (US)
Article number098001
JournalPublications of the Astronomical Society of the Pacific
Issue number1051
StatePublished - Sep 1 2023

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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