ИСТИНА

Polar-ring galaxies (PRGs) present spectacular evidence of the galaxy formation via merging or accretion of the baryon matter with different orbital angular momentum orientation. Previous catalogues of PRGs were based on the results of visual inspection of photographic or digital images and forthcoming spectral (i.e., kinematical) confirmation. The modern integral-field surveys allow us to discover external polar structures around galaxy discs directly from their peculiar kinematics without `morphological bias'. The first examples of these studies are presented here including follow-up Russian 6-m telescope observations of the MaNGA targets with the external ionized gas polar structures. Also, a set of new published results related to polar-ring phenomenon are discussed: the estimation of gas metallicity in a large sample of PRGs; the impact of shock waves in gas ionization in host discs and polar structures; the existence of strongly inclined (non-orthogonal to the host) structures; the environmental dependence of the PRG fraction; common relations between inner and outer polar structures. The impact of these results on our understanding of the galactic structure and evolution is considered.