Filabres, a new pipeline for the automatic data reduction of CAFOS direct imaging

Abstract

Filabresis a new Python pipeline created with the idea of performing the automatic reduction of direct images obtained with the instrument CAFOS, placed at the 2.2 m telescope of the CalarAlto Observatory. The goal is to provide useful reduced images through the CalarAlto Archive hosted by the Spanish Virtual Observatory. The typical workflow with Filabresconsists of the following steps: (1) Image classification (bias, flat-imaging, arc, scienceimaging, etc.); (2) Reduction of calibration images (bias, flat-imaging) and generation of combined master calibrations as a function of the modified Julian Date; (3) Basic reduction of individual science images, making use of the corresponding master calibrations (closest in time to the observation of the science target). The main reduction steps considered here are: bias subtraction, flatfieldingof the images, and astrometric calibration (performed with the help of additional software tools provided by Astrometry.netand by AstrOmatic.net). The behaviour of the data reduction is easily defined through a set of reduction rules set in a configuration YAML file, specifically built for the considered instrument and observation mode. Note, however, that the software has been designed to allow the future inclusion of additional observing modes and instruments. The software is publicly available through GitHub athttps://github.com/nicocardiel/filabres, and its documentation inhttps://filabres.readthedocs.io/.