The 8K Mosaic camera and the OSU CCD spectrograph have their own CCDS and the user is referred to the appropriate documentation.
CCD name format pixel size Notes --------------------------------------------------------------------------- Charlotte 1024x1024 24 micron thinned, backside ill. manufacturer: SITE Templeton 1024x1024 24 micron thinned, backside ill. manufacturer: SITE Echelle 2048x2048 24 micron thinned, backside ill. manufacturer: SITE Nellie 2048x2048 21 micron thick, frontside manufacturer: STIS Wilbur 2048x2048 15 micron thick, frontside manufacturer: LORAL Lurvy 512x1024 24 micron thick, frontside manufacturer: Lincoln Labs (Not used any more) ---------------------------------------------------------------------------Templeton and Echelle have the best response overall, and are the ones to use in the ultraviolet. Charlotte and Templeton use a common dewar body so they can not be used at the same time. Nellie and Wilbur have limited response at Johnson B, and have a higher cosmic ray rate than the thinned devices.
QE curves are available for Charlotte and Echelle.
Readout times are typically 30-31 seconds for the 1024x1024 devices (unbinned). Wilbur and Nellie take approximately 100 seconds when read out in the full 2048x2048 format, and the Echelle takes 120 seconds when read in the full 2048x2048 format. All devices are read through a single amplifier.
All CCDs produce 16 bit unsigned data: 0-65535 DN. Nominal values for gain and readnoise as determined during the fall of 1995 are:
CCD name gain (e/DN) readnoise (e rms) --------------------------------------------------------------- Charlotte 3.16 5.45 Templeton 3.47 5.33 (measured Oct 1996) Echelle 1.3/2.7 7.9 (measured April 1997) Nellie 2.94 4.38 Wilbur 2.25 4.73 ---------------------------------------------------------------The following table gives the angular size ("/pixel) and the field of view (arc-minutes) for these CCDs when used in direct imaging at the various foci of the MDM telescopes. These are computed using the scale factors given in the telescope manuals. They are not measured values.
2.4m Hiltner telescope f/7.5 11.528"/mm f/13.5 6.399"/mm ---------------------------------------------------------- Charlotte 0.28 4.72 0.15 2.62 Templeton 0.28 4.72 0.15 2.62 Echelle 0.28 9.44 0.15 5.24 Nellie 0.24 8.26 0.13 4.59 Wilbur 0.17 5.90 0.10 3.28 ---------------------------------------------------------- 1.3m McGraw-Hill telescope f/7.6 20.72"/mm f/13.5 11.81"/mm ---------------------------------------------------------- Charlotte 0.50 8.49 0.28 4.84 Templeton 0.50 8.49 0.28 4.84 Echelle 0.50 16.98 0.28 9.68 Nellie 0.44 14.85 0.25 8.47 Wilbur 0.31 10.61 0.18 6.05 ----------------------------------------------------------
