LoTSS jellyfish galaxies: II. Ram pressure stripping in groups versus
  clusters
  Numerous examples of ram pressure stripping in galaxy clusters are present in
literature; however, substantially less work has been focused on ram pressure
stripping in lower mass groups. In this work we use the LOFAR Two-metre Sky
Survey (LoTSS) to search for jellyfish galaxies in ~500 SDSS groups (z<0.05),
making this the most comprehensive search for ram pressure stripping in groups
to date. We identify 60 jellyfish galaxies in groups with extended, asymmetric
radio continuum tails, which are found across the entire range of group mass
from $10^{12.5} < M_\mathrm{group} < 10^{14}\,h^{-1}\,\mathrm{M_\odot}$. We
compare the group jellyfish galaxies identified in this work with the LoTSS
jellyfish galaxies in clusters presented in Roberts et al. (2021), allowing us
to compare the effects of ram pressure stripping across three decades in
group/cluster mass. We find that jellyfish galaxies are most commonly found in
clusters, with the frequency decreasing towards the lowest mass groups. Both
the orientation of observed radio continuum tails, and the positions of group
jellyfish galaxies in phase space, suggest that galaxies are stripped more
slowly in groups relative to clusters. Finally, we find that the star formation
rates of jellyfish galaxies in groups are consistent with `normal' star-forming
group galaxies, which is in contrast to cluster jellyfish galaxies that have
clearly enhanced star formation rates. On the whole, there is clear evidence
for ongoing ram pressure stripping in galaxy groups (down to very low group
masses), though the frequency of jellyfish galaxies and the strength of ram
pressure stripping appears smaller in groups than clusters. Differences in the
efficiency of ram pressure stripping in groups versus clusters likely
contributes to the positive trend between quenched fraction and host halo mass
observed in the local Universe.
