NIRSpec Observing Modes
The JWST Near Infrared Spectrograph (NIRSpec) has 4 observing modes—near-infrared multi-object spectroscopy (MOS), integral field unit (IFU) spectroscopy, fixed slits (FS) spectroscopy, and bright object time-series (BOTS) spectroscopy—covering wavelengths from 0.6 to 5.3 μm.
NIRSpec has 4 observing modes that correspond to templates in the Astronomer's Proposal Tool (APT):
- Multi-object spectroscopy (MOS) obtains simultaneous spectroscopy of multiple science sources within a 3.6' × 3.4' field of view using the micro-shutter assembly (MSA).
- Integral field unit (IFU) spectroscopy uses the integral field unit to provide spatially resolved spectroscopy over a 3" × 3" square region.
- Fixed slits (FS) spectroscopy provides 5 fixed slits for obtaining high sensitivity single object spectroscopy.
- Bright object time-series (BOTS) spectroscopy uses a 1.6" × 1.6" fixed slit aperture for observations of bright sources that require stable, high throughput time-resolved spectroscopy.