  Using the IRAM 30m radio telescope we have mapped the tidal arm feature
south-east of NGC3077 where we recently detected molecular gas in the CO
(J=1-0) and (2-1) transitions. We find that the molecular gas is much more
extended than previously thought (several kpc). The CO emission can be
separated into at least 3 distinct complexes with equivalent radii between
250pc and 700pc and all well confined over a narrow range in velocity. For one
complex we have also obtained a CO (3-2) spectrum using the KOSMA 3m radio
telescope; utilizing an LVG model we find that the kinetic temperature for this
complex must be about 10K, and the H2 volume density between 600 and
10000cm^-3. Mass estimates based on virialization yield a total mass for the
complexes of order 2-4 10^7 M_sun, i.e. more than the estimated molecular mass
within NGC3077 itself. This implies that interactions between galaxies can
efficiently remove heavy elements and molecules from a galaxy and enrich the
intergalactic medium. A comparison of the distribution of HI and CO shows no
clear correlation. However, CO is only found in regions where the HI column
density exceeds 1.1 10^21 cm^-2. HI masses for the molecular complexes mapped
are of the same order as the corresponding molecular masses. Since the tidal
arm with its molecular complexes has all the ingredients to form stars in the
future, we are thus presumably witnessing the birth of a dwarf galaxy. This
process could be important for the formation of dwarf galaxies especially at
larger look-back times in the universe where galaxy interactions may have been
more frequent.
