Data Reduction

The AAT and AAO-MQ supported 2dfdr software package handles basic reduction of KOALA data. 2dfdr takes raw files from the telescope and extracts wavelength calibrated spectra for each lenslet of the integral-field unit. For KOALA data, 2dfdr is currently able to apply some fibre chromatic and total response correction, detector response correction (flatfielding) and sky subtraction using blank sky regions within an individual observation.

A description of the data reduction process is included in the KOALA+AAOmega Manual under "Part IV: Data Reduction." Additional help with data reduction is available from Ángel López-Sánchez.

We are currently developing new Python scripts that combine and/or mosaic observations of a single source, deal with the spatial rebinning of the data onto a square spatial grid (i.e. cubing), and correct for atmospheric differential refraction. We expect these scripts to be completely functional by Semester 17A. Please contact Ángel López-Sánchez, for more information.

Additionally, some programs may need spectrophotometric flux calibration. This step will be later included in our Python scripts but it can be already achieved using standard IRAF routines.

Additional Resources

Example of reconstructing a cube and combining multiple frames using drizzling provided by the SAMI Python Package: