The operational aspects of JWST's NIRSpec instrument define how instrument-level capabilities can be applied for science. These features include target acquisition methods, dithers/nods for each observing mode, and special considerations for science observations.

The JWST Near Infrared Spectrograph (NIRSpec) enables 0.6–5.3 μm spectroscopy at resolving powers of ~100, ~1,000, and ~2,700 in multi-object spectroscopy (MOS), integral field unit (IFU) spectroscopy, fixed slit (FS) spectroscopy, and bright object time-series (BOTS) spectroscopy modes.  

These NIRSpec science modes include the following operational properties and capabilities:

• NIRSpec target acquisition

• NIRSpec dithering strategies

  • NIRSpec MOS dither and nod patterns
  • NIRSpec IFU dither and nod patterns
  • NIRSpec FS dither and nod patterns
• NIRSpec MOS operations
  • Observing process
  • Program updates
  • Catalogs and images
  • Pre-Imaging using NIRCam
  • Confirmation images
  • Slit losses
  • Wavelength ranges and gaps
  • Shutter operability
• NIRSpec IFU operations
  • MSA leakage corrections
  • Wavelength ranges and gaps
• NIRSpec FS operations
  • Wavelength ranges and gaps
• NIRSpec BOTS operations
  • Wavelength ranges and gaps
• NIRSpec auto-cals