25 new long-term variables in the GX 339-4 field: two years of MeerKAT monitoring

These are the radio light curves for the 25 new long-term variable sources found in weekly ThunderKAT monitoring of the low-mass X-ray binary GX 339-4 with MeerKAT. These data are part of a publication submitted to Monthly Notices for the Royal Astronomical Society (Driessen et al., submitted) and part of Laura's Driessen PhD thesis (the jodrell Bank Centre for Astrophysics, the University of Manchester, UK).

The observations are MeerKAT L-band observations. Each epoch is approximately 10-15 minutes long, these are the first two years of weekly monitoring, from September 2018 to the end of August 2020. The light curves have been extracted from the images using the LOFAR Transients Pipeline (TraP).

Each file contains the information for a single source. The files are formatted with columns as follows:

mjd: the modified Julian Date (MJD) of the observation. The MJD is given by MJD=JD-2400000.5 where JD is the Julian Date

f_int_median_scaled_Jy: the flux density of the source in Jansky (Jy) determined by the LOFAR TraP, after the systematic correction model has been applied (see Driessen et al. 2021)

f_int_median_scaled_err_Jy: the uncertainty on f_int_median_scaled_Jy in Jansky determined by the LOFAR TraP, after the systematic correction model has been applied (see Driessen et al. 2021)

freq_eff_Hz: the effect frequency in Hertz (Hz)

median_scaled_eta: the chi squared variability parameter for the source in the specified frequency band/subband. This parameter is defined in Driessen et al. 2021, Swinbank et al. 2015 and on the LOFAR TraP website

median_scaled_V: the modulation variability parameter for the source in the specified frequency band/subband. This parameter is defined in Driessen et al. 2021, Swinbank et al. 2015 and on the LOFAR TraP website

name: this is the name of the source as defined in Driessen et al. 2021

subband: this file contains the light curve of the source from multi-frequency synthesis (MFS) imaging of the full MeerKAT L-band (from 856 to 1712 MHz) epochs, plus 8 subband images with central frequencies: 909, 1016, 1123, 1230, 1337, 1444, 1551 and 1658 MHz. This column shows which subband or MFS the values in the row are from

The files were made using the Pandas package, so we recommend Python users load them using 

import pandas as pd
pd.read_csv(filename, comment='#')

If you use the data shared here please ensure that you cite the MNRAS paper (Driessen at al. submitted) and the Zenodo DOI: 10.5281/zenodo.5069119.

The MeerKAT telescope is operated by the South African Radio Astronomy Observatory, which is a facility of the National Research Foundation, an agency of the Department of Science and Innovation.
LND acknowledges support from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No 694745).