piexpiex / cfc

CAFOS Photometry Calibrator is a pipeline designed for an automatic calibration of astronomical images of the CAFOS instrument of the 2.2m telescope of the Calar Alto observatory.

CFC (Calibrador Fotométrico de CAFOS)

Bash and Python subroutines that perform automatic photometric calibration of images from CAFOS instrument of the 2.2m telescope at the Calar Alto Observatory (CAHA).

Requirements

-SExtractor (Source-Extractor) 2.25.0 version or later.

-PSFEx (PSF Extractor) 3.17.1 version or later.

-Astroquery.

-Astropy.

Operation mode

Description of how use the program in two different modes, one adapted to the output of filabres and the other for self-calibrated images (currently works only with images of SDSS filters).

Filabres output

it is recommended to use filabres for a correct reduction and calibration of the images.

The program works by depositing the CFC.sh file, the CFC_configuration folder and a csv file with the columns: caha_id, filter_name, program and reduction_file (for example "filabres_tree.csv") and using the following command in the UNIX terminal:

sh CFC.sh filabres_tree.csv

Images with own reduction and astrometric calibration

The program works by depositing the CFC.sh file, the CFC_configuration folder and a folder with the images to calibrate (for example "files") and using the following command in the UNIX terminal:

sh CFC.sh files

The images have to be reduced and calibrated astrometrically.

Image processing

-Estimation of the image dimensions and application of a mask (if the image has been trimed in a peculiar way, it is recommended to use the mask.py program to create a custom mask.) and identification of the filter used (at the moment it only works for SDSS filters).

-Use of SExtractor and PSFEx for the identification of the objects in the image and the estimation of their parameters.

-Application of different selection criteria to identify real objects and discard artifacts.

-Selection of the objects with the highest photometric quality and calibration by a comparison with the SDSS DR12 or APASS DR9 catalogs.

-Elaboration of a catalog associated with each image with the objects calibrated in magnitudes and different quality parameters.

Merge catalogs

To merge the obtained catalogs, you can use the command:

sh CFC.sh merge

This produces a catalog with lines of all catalogs obtained previously in a new folder called catalogs_folder/merge_catalogs.

Results

-Catalogues of objects calibrated in magnitude associated with each image of CAFOS.

-Images of source selection curves and magnitude calibration.

-Elaboration of a summary table (data_table.csv) of the photometric parameters of each image and if it has been calibrated correctly.

see the official documentation at: https://readthedocs.org/projects/cafos-photometry-calibrator

see the official repository at: https://github.com/piexpiex/CFC