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GMOS SV Modes

Here we describe the key modes of GMOS to be tested as part of System Verification (SV). The pool from which verification observations will be drawn is described in the GMOS-North SV plan and GMOS-South SV plan. These plan contains details of individual observations and describes other aspects of the system which will be tested.

GMOS has six SV modes:

  1. Direct imaging
    • Plate scale: 0.072 arcsec/pixel
    • FOV: 5.5 x 5.5 arcmin2
    • It is likely that all spectroscopic masks will be designed with the aid of direct images taken with GMOS.
  2. Long-slit spectroscopy
    • Spectral resolution: 670 - 4400 (0.5 arcsec slit)
    • Slit width: custom slits >= 0.25 arcsec width
    • Slit length: up to 5.5 arcmin
  3. Multi aperture spectroscopy
    • Up to 600 slitlets over a 5.5 x 5.5 arcmin2 FOV
    • Spectral resolution: 670 - 4400 (0.5 arcsec slit)
    • Slit width: custom slits >= 0.25 arcsec width
    • Slit length: up to 5.5 arcmin
  4. Nod-and-Shuffle
    • May be used with long-slit or MOS to improve sky subtraction
  5. Integral field spectroscopy
    • Spectral resolution: 670 - 4400
    • Integral field unit configuration: two-dimensional spectroscopy over a contiguous field of ~50 arcsec2 with 0.2 arcsec sampling. A small background field will be available at fixed separation (>1 arcmin) from the main object field for accurate background subtraction.
    • Effective slit width: ~0.27 arcsec
    • Spectrum length: up to 3000 pixels long and up to 900 spectral resolution elements per spatial sample
  6. Polarization
    • Option to be confirmed


Last update August 28, 2002; Inger Jørgensen