# Reproduction package for the paper "Searching for low radio-frequency gravitational wave counterparts in wide-field LOFAR data"

by Gourdji et al. (2021)
arXiv:2105.07413
DOI: 10.1093/mnras/stab3197

## Raw data
The interferometric LOFAR visibilities used to derive the final images analyzed in this paper can be downloaded from the LOFAR Long Term Archive under project code LC8_005 (https://lta.lofar.eu).

## Software
- Calibration: the visibilities were calibrated using PREFACTOR as part of the publically available LOFAR imaging software (lofim) version 3_0_10 (https://www.astron.nl/lofarwiki/doku.php?id=public:user_software:start). Example parsets used for calibrator and target data are included in data_reduction_parsets.gz

- Imaging: the calibrated data were imaged using WSClean (https://gitlab.com/aroffringa/wsclean/) version 1.12 with settings as follows:

-size 8192 8192 -mgain 0.8 -auto-mask 10 -pol I -maxuv-l 8000 -channelsout 3 -auto-threshold 1 -j 10 -weight briggs -0.5 -scale 5asec -niter 100000 -cleanborder 0 -apply-primary-beam -use-differential-lofar-beam -joinchannels -no-update-model-required -reorder -weighting-rank-filter 3.0 -fitbeam

The image analysis (source extraction and transient search) was performed using TraP, version 4.0 (https://tkp.readthedocs.io/en/latest/). An example job_params.cfg file is included in data_reduction_parsets.gz and indicates the TraP settings used.

## Figures and Tables
A Jupyter notebook is stored in figures_and_tables.gz and reproduces the figures of this paper. Also included are the necessary data files imported by the notebook as well as files containing the data shown in Tables B1 and B2.
