Make a processed bias

Remember to work from the redux directory.

Let’s define a few variables:

procbias = 'S20060314S0091_bias.fits'
rawdir = '../tutorial_data/'
caldir = '../calibrations/'

The settings above and the content of the bias list are the only things that need to be modified if you were to run the commands below on a different set of biases.

To create the processed bias, we use the gbias task in the gmos package. In the snippet below, we delete any outputs from a previous run, create the bias, then copy the processed bias to the directory where we will store the processed calibrations.

In this tutorial, the processed bias will be stored in a different directoy, same for the sensitivity function. The motivation for storing the processed calibration safely out of redux is that later on, if we decide to restart the science reduction from scratch, we can just delete everything in redux knowing that the master bias and the sensitivity function are safe and won’t have to be created again. This is preference, not a requirement.

imdelete(procbias)
imdelete('g@bias.lis')

gbias('@bias.lis', procbias, rawpath=rawdir, fl_vardq='yes')
copy(procbias, caldir)

Finally, it is recommended to inspect the result. After all, that master bias will affect every other frames we will reduce, might as well make sure it looks okay.

gdisplay(procbias, 1, fl_paste='no')