FLAMINGOS I Performance and Use 

Status and availability: FLAMINGOS I has been loaned to Gemini by the University of Florida. In semester 2002B it will be available in service observing mode only, on Gemini South.  For target RA constraints see the instrument calendar.
Modes of operation: FLAMINGOS I will have the following modes available in 2002B: 
  • Wide-field imaging 
  • Grism long-slit spectroscopy with various slits in H+K window e.g. R=1000 (0.16 arcsec slit) and R=350 (0.47 arcsec slit) 
  • Grism long-slit spectroscopy with various slits in J+H window (using H+K grism + J+H filter) with J-band dispersed in 2nd order, H-band in 1st. e.g. with 0.47 arcsec slit, R=475 at J, R=320 at H. 
Elements of FLAMINGOS I Specific elements of FLAMINGOS I include: 
  • Detector 
  • Filters
    • Standard broadband J, H, K, and K(short) filters. 
  • Grisms and slits
    • H+K grism covers 1.5-2.4um at one setting. Spectral resolving power is R~350 with a 6-pixel slit (0.47 arcsec) and R~1000 with a 2-pixel wide slit (0.16 arcsec).
    • J+H grism (not available)
    • R=2400 grism (not available)
    • Slit options: 0.23" and 0.47" slits are 148" in length (3 and 6 pixels wide). 0.16", 0.7", 0.94", and 1.56" slits are 113" in length (2, 9, 12, and 20 pixels wide). 
  • Mask making (imaging, target identification, schedule) (not available
  • Wavefront sensors (WFS) and guide stars
    • The Peripheral WFS (PWFS) is required for all observations. In most cases the PWFS will partially vignette part of the imaging field of view (follow the link for more details). The width of the vignetted zone (0-100% obscuration) is about 200 arcsec and varies roughly linearly with distance from the probe arm e.g. 50% at 100 arcsec. Proposers should pay particular attention to limits imposed by the small patrol areas and consider whether some vignetting in the outer field-of-view is acceptable for the science program. In almost all cases PWFS2 will be used with FLAMINGOS as it is closer to the focal plane and has a larger unvignetted patrol radius. 
Sensitivity: Preliminary sensitivity tables for imaging and spectroscopy are available. 

The estimated image quality delivered to the instrument is given as part of the observing condition constraints.

Observing overheads: Current estimates are that the overheads associated with each new science target (for target acquisition, telescope, WFS and instrument re-configuration etc) total 15 min for imaging and 30 min for spectroscopy. For exposure times of 60 sec or greater the approximate on-source efficiency is 70% (i.e. 30% of the elapsed time is used for telescope offsetting, WFS re-acquisition, detector readout etc). If shorter individual exposure times are required to avoid saturation of bright objects the on-source efficiency will be reduced. Assume 50% efficiency for individual exposure times less than 30 seconds

These overheads should be included in the time requested for each observation. Note that mosaicing multiple FLAMINGOS fields may require additional overheads, as it is in most cases not possible to use the same guide star at multiple pointings and avoid significant vignetting. Therefore the 15 minute overhead for WFS reconfiguration will be incurred for each pointing. Please factor this additional overhead into the time justification.

Calibration: A basic calibration set will be obtained for each observation.

Information, catalogues, and search engines for  photometric and  spectroscopic standard stars are available.

Target Acquisition: See the generic target acquisition scenarios


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Last update February 14, 2002; Michael Ledlow