MDM Facility CCD Detectors

MDM Observatory has right now 2 (until further notice(Nellie & Templeton)) facility CCDs available for general use. These CCDs can be used in imaging mode at either telescope, and on the Modular and MkIII spectrographs. All are Leach GenIII controller systems operated by the owl (from Astronomical Research Camera Inc.) package.

In August 2011 we commisioned Bob Leach to upgrade our data taking systems which involed down time of the facility ccd's.
Nellie and Templeton have been used at both telescopes. Soon there is hope of having the Echelle and Wilbur
being available.

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
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Templeton 1024x1024 24 micron thinned, backside ill. (Upgrade by Astronomical Research Cameras Inc.)
	manufacturer: SITE

Echelle 2048x2048 24 micron thinned, backside ill. (Having a problem right now Stay tuned)
	manufacturer: SITE

Nellie 2048x2048 21 micron thick, frontside (Upgrade by Astronomical Research Cameras Inc.) Sept. 2011
	manufacturer: STIS

Wilbur 2048x2048 15 micron thick, frontside (At Astronomical Research Cameras Inc.)
	manufacturer: LORAL

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Templeton and Echelle have the best response overall, and are the ones to use in the ultraviolet. 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 Templeton and Echelle.

Readout times are typically 28-30 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)
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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 
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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
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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
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1.3m McGraw-Hill telescope

	f/7.6 20.72"/mm f/13.5 11.81"/mm
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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
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Updated: 2012 July 06 (Barr/MDM)