  ATCA HI and radio continuum observations of the peculiar southern galaxy
IC2554 and its surroundings reveal typical signatures of an interacting galaxy
group. We detected a large HI cloud between IC2554 and the elliptical galaxy
NGC3136B. The gas dynamics in IC2554 itself, which is sometimes described as a
colliding pair, are surprisingly regular, whereas NGC3136B was not detected.
The HI cloud, which emerges from IC2554 as a large arc-shaped plume, has a size
of about 30 kpc, larger than that of IC2554. The total HI mass of the IC2554
system is about 2 x 10^9 Msun, a third of which resides in the HI cloud. It is
possible that tidal interaction between IC2554 and NGC3136B caused this
spectacular HI cloud, but the possibility of IC2554 being a merger remnant is
also discussed. We also detected HI gas in the nearby galaxies ESO092-G009 and
RKK1959 as well as an associated HI cloud, ATCA J1006-6710. Together they have
an HI mass of about 4.6 x 10^8 Msun. Another new HI source, ATCA J1007-6659,
with an HI mass of only about 2.2 x 10^7 Msun was detected roughly between
IC2554 and ESO092-G009 and corresponds to a face-on low surface brightness
dwarf galaxy. Star formation is evident only in the galaxy IC2554 with a rate
of about 4 Msun/yr.
