SOFI (SON OF ISAAC)
===================

  Instrument Overview                                                         
  ===================                                                         
    SOFI (Son of Isaac) is the infrared spectrograph and imaging camera on the
    NTT.  The instrument is equipped with a Hawaii HgCdTe 1024x1024 array with
    squared 18.5 micron pixels, sensitive to light within 0.9-2.5 micron      
    range. The peak quantum efficiency is 65%, the gain is about 5.4 e/ADU,   
    and the read out noise is about 2.1 ADU. The array is linear to less than 
    1.5% for signal below 10000 ADU.                                          
                                                                              
    The instrument offers the following observing modes:                      
                                                                              
     - Imaging with plate scales of 0.144, 0.273 and 0.288 arcseconds/pixel   
    using broad and narrow band filters in the wavelength range 0.9 to 2.5    
    microns.                                                                  
                                                                              
     - Low resolution (R=600) and medium resolution (R=1200-1500), 0.93-2.54  
    micron spectroscopy with fixed width slits of 0.6, 1 and 2 arcseconds.    
                                                                              
     - 0.9-2.5 micron imaging polarimetry.                                    
                                                                              
     - High time-resolution imaging in burst and fast photometry mode with    
    integration times of the order of a few tens of milliseconds via hardware 
    windowing of the detector array.                                          
                                                                              
    Slits (arcsec):   2 x 290    1 x 290   0.6 x 290                          
                                                                              
    Grisms:                                                                   
                                                                              
    Grisms         Order   Dispersion   Resolution    Wavelength Range        
    GB Grism Blue  1        6.96        1000          0.95-1.64               
    GR Grism Red   1       10.22        1000          1.53-2.52               
    HR Grism       3        4.63        2200          2.00-2.30               
    HR Grism       4        3.44        1500          1.49-1.81               
    HR Grism       5        2.71        1400          1.20-1.28               
    HR Grism       6        2.32        1400          1.17-1.24               
    HR Grism       7        1.87        1400          0.89-0.93               
    HR Grism       8        1.58        1400          0.86-0.95               
    (resolution shown for 0.6' slit)                                          
                                                                              
    Note:  SOFI is called Son of Isaac because it was developed and built     
    shortly                                                                   
    after the instrumental study of ISAAC, the Infrared Spectrometer And Array
    Camera built by ESO for use at the VLT.                                   
                                                                              
    Reference:                                                                
                                                                              
    Moorewood, A., J.-G. Cuby, and C. Lidman, SOFI sees first light at the    
    NNT, Messenger 91, 9-13, 1998.

References
==========

Moorewood, A., J.-G. Cuby, and C.       
        Lidman, SOFI sees first light at the NNT, Messenger 91, 9-13, 1998.