Exploring the properties of low-frequency radio emission and magnetic
  fields in a sample of compact galaxy groups using the LOFAR Two-Metre Sky
  Survey (LoTSS)
  We use the LOFAR Two-metre Sky Survey (LoTSS) Data Release I to identify the
groups of galaxies (and individual galaxies) from the Hickson Compact Groups
and Magnitude Limited Compact Groups samples that emit at the frequency of
150\,MHz, characterise their radio emission (extended or limited to the
galaxies), and compare new results to earlier observations and theoretical
predictions. The detection of 73 systems (and 7 more -- probably) out of 120,
of which as many as 17 show the presence of extended radio structures, confirms
the previous hypothesis of the common character of the magnetic field inside
galaxy groups and its detectability. In order to investigate the future
potential of low-frequency radio studies of galaxy groups, we also present a
more detailed insight into four radio-emitting systems, for which the strength
of the magnetic field inside their intergalactic medium (IGM) is calculated.
The estimated values are comparable to that found inside star-forming galaxies,
suggesting a dynamical and evolutionary importance of the magnetic field in
galaxy groups.
