Tidal bridge and tidal dwarf candidates in the interacting system Arp194
  Arp194 is a system of recently collided galaxies, where the southern galaxy
(S) passed through the gaseous disc of the northern galaxy (N) which in turn
consists of two close components. This system is of special interest due to the
presence of regions of active star-formation in the bridge between galaxies,
the brightest of which (the region A) has a size of at least 4 kpc. We obtained
three spectral slices of the system for different slit positions at the 6-m
telescope of SAO RAS. We estimated the radial distribution of line-of-sight
velocity and velocity dispersion as well as the intensities of emission lines
and oxygen abundance $12+\log(\mathrm{O/H})$. The gas in the bridge is only
partially mixed chemically and spatially: we observe the O/H gradient with the
galactocentric distances both from S and N galaxies and a high dispersion of
O/H in the outskirts of N-galaxy. Velocity dispersion of the emission-line gas
is the lowest in the star-forming sites of the bridge and exceeds 50-70 km/s in
the disturbed region of N-galaxy. Based on the SDSS photometrical data and our
kinematical profiles we measured the masses of stellar population and the
dynamical masses of individual objects. We confirm that the region A is the
gravitationally bound tidal dwarf with the age of $10^7 - 10^8 $ yr, which is
falling onto the parent S- galaxy. There is no evidence of the significant
amount of dark matter in this dwarf galaxy.
