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NICMOS Synthetic Flatfield Request Form

NICMOS Temperature-Specific Flatfield Request Form

WARNING: The flatfield normalizations were wrong between Jan. 23, 2002 and Oct. 16, 2002, 17:30 EDT. However (since the photometric keywords in the headers continue to be incorrect) this should only affect you if you were trying to make your own photometric/DQE corrections for temperature with these flats. The post-NCS flats in CDBS are normalized correctly!

This page has been set up to facilitate the making of flatfield reference files corresponding to a specific temperature. The detector quantum efficiency changes with respect to temperature in each pixel, thus affecting flatfield variations absolutely and relatively across each chip. A temperature sensitive flat is essential to the calibration process.

This form does not currently accomodate polarizers or grisms.

Below, please choose the camera with which the observations were made, the filter in use, and the temperature at which the observations were made.

The keyword NDWTMP11 (for cameras 1 and 2) or NDWTMP13 (for camera 3), in the headers of the _spt file corresponding to the dataset should be a good first estimate of the effective temperature. There is a separate temperature reading in the _spt file for each non-destructive readout in a multiaccum sequence.)

You should first try temperatures precise to 0.05 degrees K, and only more precise than that if further examination of the data warrants it, as the temperature fluctuates on the order of a tenth of a degree during the timespan of any exposure. After you fill in the form and submit it, a page should appear with a direct link to your new reference file. The process can take a minute or two. Do NOT impatiently hit the 'stop' button on your browser!



Temperature (K):