Produce difference imaging light curves for the dark energy survey in an automated fashion.
Needs to be run using the EUPS environment after installing packages in the source.me
file. Note this assumes the paths to the setup and config files are ${HOME}/eups/desdm_eups_setup.sh
and ${HOME}/.desservices.ini
.
The -c
flag can be used to specify the CCD. The -n
flag specifies the number of threads to use. Due to invalid keywords in image headers, supressing warnings with --nowarn
is recommended. Example:
./desdia --field SN-C3 -n 30 -c 1 -w /data/des80.a/data/${USER}/ --nowarn
./desdia --field COSMOS -n 30 -c 1 -w /data/des80.a/data/${USER}/ -s 2 --nowarn
./desdia --field DECADE-S-CVZ -n 30 -c 1 -s 8 -w /data/des80.a/data/${USER}/ --nowarn
No COSMOS images were taking in the default season (Y6), so add -s 2
to change the template season to Y2.
For the wide-area survey, specify the pointing number (value from 0-2038; see y3point.csv
file). Each pointing will be split into regions (or a CCD if specified with the -c
flag) using a template constructed from Y3 pointings:
./desdia --survey 1 -n 30 -w /data/des80.a/data/${USER}/ --nowarn
If you are only interested in a single target, the code will find the pointing and CCD number for you:
./desdia --survey TARGET --ra 337.653325476 --dec -0.110275781 -n 30 -w /data/des80.a/data/${USER}/ --nowarn
The difference images and catalogs will be saved in the output directory. The reduced images will be downloaded and processed in the work directory. The output is a list of sextractor-like catalogs in the field for each CCD SN-C3/cat_c?.dat
. Each line corresponds to a measurement, so they need to be combined and matched using external software to construct light curves. The catalogs are constructed using forced photometry from the template image with a 5" aperture. Additionally, detection can be done on the difference images to discover transients.