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Two types of spectroscopy are possible with FLAMINGOS-2 and its selection of gratings:


  • Long-slit spectroscopy with longslit masks of width 1-pix, 2-pix, 3-pix, 4-pix, 6-pix, 8-pix. They have length ~4.4' (263", 1460 pixels) in the standard f/16 (non-AO) mode.

The broad band filters Y, K-long, J, H, Ks are permanently installed.

We expect to have two narrower band filters (wavelengths to be determined) also installed at any given time.  There is another upgrade path being investigated for the installation of a dual-etalon tunable narrow-band filter to be used with the f/33 GeMS system, as well as the use of the instrument fed by directly the AO beam.




  • Two lower resolution grisms (JH and HK) with peak R~1300 and simultaneously covering the J&H or H&K bands.
  • One higher resolution grism with peak R~3200 (two pixel) giving complete coverage of one (Y or J or H or Ks or K-long) near-IR band at a time.
  • The achieved resolution averages are R~1000 within 70% of the JH and HK ranges, and R~2900 within the ranges J, H or Ks/K-long. We recommend PIs to consult the grisms link to obtain more information about how the spectral resolution changes with  wavelegth. After the fixes done in 2014, the resolution is now constant across the whole slit length.   


Here you can find more details about the Science detector, and the  Filters