Prague Relativistic Astrophysics

Anna Saburova

On the example of three strongly interacting systems (Arp
270, Arp 194, NGC4656) we study the star forming sites in
the main bodies of the galaxies and in their vicinities:
gas and stellar kinematics, metal abundance and stellar age.
For this purpose we used the long-slit spectral observations
carried out at the Russian 6m telescope. All three systems
are very different in their star forming history. In Arp 270
the emission gas is well chemically mixed, whereas in Arp
194 there are strong velocity and abundance gradients
between the galaxies. In Arp 194 and NGC4656 we observe the
evidences of continuing gas accretion onto the galaxies. In
Arp194 we found a tidal dwarf candidate falling back into
the parent galaxy. The close low surface brightness
satellite interacting with NGC 4656 in contrast appears to
be a metal-poor discy dwarf galaxy resembling ultra-diffuse
galaxies where the mass of stellar population is low in
comparison with the mass of dark matter and HI.