IAU Symposium Abstract S186-032P

Local and high-redshift polar-ring galaxies

1 Astronomical Institute of St.Petersburg State University, Russia < resh@aispbu.spb.su >

We discuss the properties of all presently known low-redshift polar-ring galaxies (PRGs) - early-type galaxies with a large-scale ring of gas, dust and stars orbiting nearly perpendicular to the major axis of the host galaxy. We present observational and theoretical arquments in favour of polar rings formation during interactions and mergings between galaxies.. We summarize the characteristics of two peculiar objects at z ~ 1 selected in the Hubble Deep Field as possible candidates to high-redshift PRGs. We found that these objects are very close to low-redshift PRGs by general photometric characteristics. The presence of two good candidates to PRGs in the Hubble Deep Field suggests that the volume density of PRGs does rise with redshift and supports a steeply increasing galaxy interaction rate at z ~ 1.