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
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first flag "A" means the file has been archived by DADS and can be found in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
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.