Intergalactic magnetic fields in Stephan's Quintet
  We present results of the VLA radio continuum total power and polarised
intensity observations of Stephan's Quintet at 1.43 and 4.86 GHz along with
complementary 4.85 and 8.35 GHz Effelsberg observations. Our study shows a
large envelope of radio emission encompassing all the member galaxies and hence
a large volume of intergalac- tic matter. Infall of the galaxy NGC 7318B
produces a ridge of intergalactic, polarised emission, for which the magnetic
field strength was estimated as 11.0 \pm 2.2 {\mu}G, with an ordered component
of 2.6 \pm 0.8 {\mu}G. The energy density of the field within the ridge area is
of the same order as estimates of the thermal component, implying a significant
role of the magnetic field in the dynamics of the intergalactic matter. We also
report that the tidal dwarf galaxy candidate SQ-B possesses a strong and highly
anisotropic magnetic field with the total strength being equal to 6.5 \pm 1.9
{\mu}G and an ordered component reaching 3.5 \pm 1.2 {\mu}G, which is
comparable to that found in normal-sized galaxies.
