The Near Infrared Imager and Slitless Spectrograph for the James Webb Space Telescope. I. Instrument Overview and In-flight Performance
René Doyon, Chris J. Willott, J. B. Hutchings, Anand Sivaramakrishnan, Loïc Albert, David Lafreniére, Neil Rowlands, M. Begoña Vila, A. R. Martel, Stephanie LaMassa, David C. Aldridge, Étienne Artigau, Peter J. Cameron, P. Chayer, Neil J. Cook, Rachel Cooper, Antoine Darveau-Bernier, J. Dupuis, Colin Earnshaw, Néstor Espinoza, Joseph Filippazzo, A. W. Fullerton, D. Gaudreau, Roman Gawlik, Paul Goudfrooij, C. S. Haley, Jens Kammerer, D. J. W. 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 F. Rowe, Arpita Roy, Niladri Roy, Karl Saad, Sangmo Tony Sohn, Geert Jan Talens, D. 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
Abstract
Abstract 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 μ m, (3) single-object cross-dispersed slitless spectroscopy (SOSS) enabling simultaneous wavelength coverage between 0.6 and 2.8 μ m 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 μ m 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 μ m 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.