The JWST integral field spectroscopy mode enables spectral imaging over small fields of view. The NIRSpec integral field unit (IFU) is designed for studies of astronomical targets that are extended over a few arcseconds, or for sampling small regions of more extended objects.

The JWST NIRSpec integral field spectroscopy (IFU) science mode operations includes applicable target acquisition methods, dithers and nods, and special considerations relevant to IFUs. Integral field spectroscopy using the NIRSpec integral field unit (IFU) delivers spectral information for every spatial position across a 2-dimensional field.

Integral field units (IFUs) combine imaging and spectroscopic capabilities to acquire spatially resolved 2-dimensional spectroscopy in a single astronomical exposure.

The continuum limiting sensitivity in IFU (upper) and MOS/FS (lower) mode is the flux required for a point source to reach S/N = 10 in ~10 ksec (10 exposures on source of 14 groups (MOS) or 17 groups (IFU) and 1 integration using NRSIRS2 readout mode).

This page describes how to simulate IFU mode data and spectral datacubes for JWST’s NIRSpec IFU and MIRI MRS. IFU support is a relatively recent addition, and efforts are still in progress to refine and improve the fidelity of IFU mode simulations. These instruments have a mode attribute, which can be set to either ‘IFU’ or ‘imaging’.

2021年5月28日 · The Integral Field Unit (IFU) of the NIRSpec instrument allows for spectral imaging of extended astronomical objects. A key element of the IFU is the image slicer, which cuts the 3 arcsec × 3 arcsec field of view into 30 slices of 0.1 arcsec × 3 arcsec.

The IFU Roadmap guides the reader, step by step, through the process of creating a JWST observing program that uses the MIRI medium resolution spectrometer (MRS) and/or the NIRSpec IFU. Whichever IFU the reader decides to use, there are a sequence of steps to follow for creating an observing program for the chosen IFU (s).

2023年9月19日 · The overall calibration status and estimated accuracy of NIRSpec IFU spectroscopic observations are described in this article; please also see the article on known issues affecting NIRSpec IFU data. Date: 19 Sept 2023. There is better than 5% absolute flux accuracy measured for the combined spectrum from the 4-point nodding pattern.

Instructions are provided for filling out the JWST APT observing template for the MIRI MRS and NIRSpec IFU Observations of Cassiopeia A example science program, where MIRI MRS and the NIRSpec IFU are used to obtain medium resolution spectra of knots in the Cassiopeia A supernova remnant. Example Science Program #26 APT Guide. On this page.

The Near Infrared Spectrograph (NIRSpec) on board of the James Webb Space Telescope (JWST) will be equipped with an Integral Field Unit (IFU) which will allow the two-dimensional spectral characterization of astronomical ob-jects with unprecedented depths, especially in the 2-5 micron wavelength range.