Flat-Fields Elixir Real Time Log
Run ID: 21Bm05

Last updated: Wed Dec 1 12:07:55 HST 2021

FilterNumber of ImagesTotal Flux (ADU)Average Flux (ADU)

This log is based on the latest information from archived images only.

The table at the top presents statistics in each filter for the flat-fields acquired so far in the current observing run. The color code is as follow: there needs to be at least 20 individual images to efficiently rejects transients when stacking the data while creating the master flat-field at the end of the run. There needs to be at least 400,000 counts in the final stacked image to beat down the photon noise. If one of those two constraints is not met, then the line is highlighted in red, indicating that more flat-fields need to be acquired in that band. When both conditions are met, the lines turn green (but it sure does not hurt to take more flat-fields though, more flat-fields is always better). The right column gives the average flux per exposure, a good value is between 10,000 and 20,000 ADUs. Flat-fields taken with MegaCam must not be taken above 20,000 ADUs in order to minimize slight non-linearity effects in the signal processing.

For each filter, individual information on each image is given in the following tables. The fields Image, HST Observing Date, Field, Run_ID & Elx_ID are self-explanatory. Exp. T. stands for the Exposure Time, F for the filter,

The Elixir Real-Time flags (e.g. "A M L R S") are meant to show the status of each image within the Elixir pipeline. The first flag "A" means the file has been archived by DADS and can be found in "/h/archive/current/instrument/megaprime". The second flag "M" means that the archive deamon has created a link in "/data/kapu/elixir/megaprime" and this link has been detected by Elixir. The third flag "L" means that the given image (the link) can be found in "/data/elixir2/rawdir/ultracam/ERUNID" with ERUNID the Elixir Run ID for the current run. The fourth flag "R" means that the image has been registered in the Elixir database. The fifth flag "S" means that the image has been successfully analyzed by the image statistic function.

If a process fails along the line, a "X" flags the problem and the red color is applied to that image.

The last column gives the sky level measured above the bias level on the CCD 13 of the image.