  We report radio continuum and 21cm HI observations using the Giant Metrewave
Radio Telescope of the group Ho124 comprising four late-type galaxies, NGC2820,
Mrk108, NGC2814 and NGC2805. Three of the galaxies have clearly undergone tidal
interactions as seen from the various morphological tidal signatures whereas
other features in the group members appear to be due to ram pressure. Here, we
describe four interesting results:(a) detection of the tidal radio continuum
bridge at 330 MHz connecting the galaxies NGC2820+Mrk108 with NGC2814 with a
spectral index of -1.8. The radio bridge was discovered by van der Hulst &
Hummel (1985) who reported a spectral index of -0.8.(b) Detection of various
tidal features including a possible tidal dwarf galaxy.(c) Sharp truncation in
the HI distribution in the south of NGC2820 and in the HI & radio continuum in
the north of NGC2814. The optical disks in both the cases look undisturbed. (d)
Detection of a large one-sided HI loop to the north of NGC 2820. No radio
continuum emission or Halpha emission is detected. We discuss various scenarios
for the origin of this loop. The central starburst scenario is not supported
due to lack of ionized gas in the loop. For an electron density of 4x10^(-4)
cm^-3 we estimate the ram pressure force of the IGrM to be comparable to the
gravitational pull of the disk of NGC2820. We suggest that the loop could have
formed by ram pressure stripping if tidal effects had reduced the surface
density of HI in NGC2820. Finally we suggest that the evolution of the Ho124
group may be governed by both tidal forces due to the interaction and ram
pressure due to motion of the member galaxies in the IGrM and that the IGrM
densities might not be too low (>~4x10^(-4)cm^-3). This should be verified by
other observations.
