CFHT, Instruments, Detectors, CCDs, EEV1

CFHT EEV CCDs - Fringing information

Here are FITS files of flat field exposures taken with our high-resolution spectrograph Gecko and the thin chip EEV2 (not EEV1). EEV2 actually has worse fringing than EEV1, but EEV1 still suffers from fringing.

FITS file for 6286Å, center of order 9, about 100Å coverage

FITS file for 7071Å, center of order 8, about 115Å coverage

FITS file for 8082Å, center of order 7, about 130Å coverage

FITS file for 9429Å, center of order 6, about 150Å coverage



Here are GIF files of cuts showing the fringes:

Column 120 of flat taken at 7071Å, showing peak-to-peak variations of roughly 3000, over an average of about 27000 (3000/27000=11%)

Column 118 of flat taken at 8082Å, showing peak-to-peak variations of roughly 8000, over an average of about 22000 (8000/22000=36%)

Column 119 of flat taken at 9429Å, showing peak-to-peak variations of roughly 9000, over an average of about 10000 (9000/10000=90%)