Spectral observations of the systems with the disturbed spiral arms: Arp
  42, Arp 82 and Arp58
  We study three Arp' systems of peculiar galaxies: Arp 42 (NGC 5829), Arp 82
(NGC 2535/36) and Arp 58 (UGC 4457), using the long-slit spectral observations
carried out at the 6m telescope BTA of Special Astrophysical Observatory. Arp
82 and Arp 58 are the M51-type systems. In the third system - Arp 42, there are
two extremely luminous kpc-sized clumps observed at the ends of the bifurcated
spiral arm, however the source of perturbations remains unknown. From the
emission line measurements we analyzed the distribution of gas line-of-sight
(LOS) velocity, velocity dispersion and gas-phase metallicity along the slits
estimated by different methods. A special attention is paid to the young
regions of star formation at the peripheries of the galaxies and in tidal
debris, their connection with gas kinematics and abundance. All three systems
show the signs of velocity disturbances and the presence of regions of locally
enhanced gas velocity dispersion, as well as the regions of diffuse ionized
gas. A distribution of oxygen reveals shallow radial abundance gradients,
typical for interacting systems. A faint spiral-like branches of tidal bridges
which are observed in NGC 2535 and UGC 4457 may represent the remnants of
pre-existing "old" mode of spiral waves.
