학술논문
The Near Infrared Imager and Slitless Spectrograph for the James Webb Space Telescope. I. Instrument Overview and In-flight Performance.
Document Type
Article
Author
René, Doyon; Willott, Chris J.; Hutchings, John B.; Sivaramakrishnan, Anand; Albert, Loïc; Lafrenière, David; Rowlands, Neil; Vila, M. Begoña; Martel, André R.; LaMassa, Stephanie; Aldridge, David; Artigau, Étienne; Cameron, Peter; Chayer, Pierre; Cook, Neil J.; Cooper, Rachel A.; Darveau-Bernier, Antoine; Dupuis, Jean; Earnshaw, Colin; Espinoza, Néstor
Source
Subject
*SPECTROGRAPHS
*ANGULAR distance
*BINARY stars
*SPACE vehicles
*PHOTOMETRY
*SPECTROMETRY
*SPACE telescopes
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Language
ISSN
0004-6280
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. [ABSTRACT FROM AUTHOR]