lofar_helpers

LOFAR helper scripts

These scripts were developed for reducing LOFAR data in the following peer-reviewed publications:

• Study of the bridge between galaxy clusters A399 and A401 (de Jong et al. 2022): https://arxiv.org/abs/2209.13930
• Producing the deepest sub-arcsecond wide-field image of ELAIS-N1 (de Jong et al. 2024): https://arxiv.org/pdf/2407.13247v1
• Improvements for the LOFAR-VLBI pipeline (de Jong et al. 2025): https://arxiv.org/pdf/2508.12115

Some of these scripts have been integrated in PILOT: https://github.com/LOFAR-VLBI/pilot \

Install with: pip install -v git+https://github.com/jurjen93/lofar_helpers.git
This gives you the following command line functions:

• split_polygon_facets -> Split a ds9 region file with multiple polygons into individual region files for each polygon.
• cut_fits_with_region -> Cut a FITS file with a ds9 region file.
• concat_with_dummies -> Concatenate MeasurementSets using dummies for missing frequency bands.
• remove_flagged_stations -> Remove 100% flagged stations from the MeasurementSet
• applycal -> Perform an applycal with DP3, taking into account corrections for beam directions

Dependencies

The scripts in this repository depend on standard LOFAR and astronomy software, such as DP3, astropy, WSClean and more. It is strongly advised to download the latest FLoCs singularity image: https://tikk3r.github.io/flocs/

Contact

Let me know if you have any issues or suggestions for improvements. You can contact me on: jurjendejong(AT)strw.leidenuniv.nl

Acknowledgments

This repository has been developed with support from the CORTEX project (NWA.1160.18.316), part of the research programme NWA-ORC which is (partly) financed by the Dutch Research Council (NWO).