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GMOS-S Array

The GMOS South detector array consists of three 2048x4608 EEV chips arranged in a row. The table below gives a summary of the current detector/controller characteristics.

Array EEV
Pixel format 6144x4608 pixels
Array layout Three 2048x4068 chips in a row with ~0.5mm gaps
Pixel size 13.5 microns square; 0.073 arcsec/pixel
Spectral Response approx 0.36 to 0.93 microns [ data / plot ]
Bias level Bias image
Flat field response Fringe images  Flat field images
Readout time See observing overheads page
Chip CCD 01 CCD 02 CCD 03
Chip ref no. EEV 2037-06-03
EEV 8194-19-04 EEV 8261-07-04
Dark current* 3 e-/pix/hr
2 e-/pix/hr 3 e-/pix/hr
Full Well ** 125 ke-
125 ke- 125 ke-
Fringing at 900nm *** 73%
68% 67%

* Dark current measured at -113C by Gemini Observatory.
** Saturation can be avoided by assuming 100ke- for all chips
*** (peak-valley)/mean, measured from images taken at Gemini

Readnoise and Gain Values

The table below gives the gain/read-noise values for the current GMOS EEV CCDs measured in September 2006 after a replacement of the video boards installed in the SDSU controller. Only the setting for the best amplifiers are listed (3-amp mode). The normal setting for science observations is slow read and low gain. For the full table of read-noise and gain values at all settings and for all amps, click here. Note: GMOS South data obtained before September 1, 2006 should use the previous gain/read-noise values.

Readout  Gain CCD 01 (left amp)
CCD 02 (left amp)
CCD 03 (right amp)
rate level Gain (e-/DN) noise (e- rms)Gain (e-/DN)
noise (e- rms)
Gain (e-/DN)
noise (e- rms)
Fast High 5.054
6.84
5.051
7.35
4.833
7.88
" Low 2.408
4.49
2.295
4.42
2.260
4.09
Slow High 4.954
5.70
4.532
4.81
4.411
4.34
" Low 2.372
3.98
2.076
3.85
2.097
3.16