The Near-Infrared Spectrograph (NIRSpec) on the James Webb Space Telescope

• Published in: Astronomy and astrophysics (Berlin) Vol. 661
• Main Authors: Ferruit, P, Jakobsen, P, Giardino, G, Rawle, T, Alves de Oliveira, C, Arribas, S, Beck, T L, Birkmann, S, Böker, T, Bunker, A J, Charlot, S, de Marchi, G, Franx, M, Henry, A, Karakla, D, Kassin, S A, Kumari, N, López-Caniego, M, Lützgendorf, N, Maiolino, R, Manjavacas, E, Marston, A, Moseley, S H, Muzerolle, J, Pirzkal, N, Rauscher, B, Rix, H-W, Sabbi, E, Sirianni, M, Te Plate, M, Valenti, J, Willott, C J, Zeidler, P
• Format: Journal Article
• Language: English
• Published: EDP Sciences 2022
• Subjects: Astrophysics; Instrumentation and Methods for Astrophysic; Sciences of the Universe; space vehicles: instruments; infrared: general; instrumentation: spectrographs
• ISSN: 0004-6361; 1432-0756
• DOI: 10.1051/0004-6361/202142589

The near-infrared spectrograph (NIRSpec) on the James Webb Space Telescope (JWST) offers the first opportunity to use integral-field spectroscopy from space at near-infrared wavelengths. More specifically, NIRSpec's integral-field unit can obtain spectra covering the wavelength range 0.6−5.3 µm for a contiguous 3.1 × 3.2 sky area at spectral resolutions of R ≈ 100, 1000, and 2700. In this paper we describe the optical and mechanical design of the NIRSpec integral-field spectroscopy mode, together with its expected performance. We also discuss a few recommended observing strategies, some of which are driven by the fact that NIRSpec is a multipurpose instrument with a number of different observing modes, which are discussed in companion papers. We briefly discuss the data processing steps required to produce wavelength-and flux-calibrated data cubes that contain the spatial and spectral information. Lastly, we mention a few scientific topics that are bound to benefit from this highly innovative capability offered by JWST/NIRSpec.