DOI

We discuss the integrated kinematic parameters of 20 M 51-type binary galaxies. A comparison of the orbital masses of the galaxies with the sum of the individual masses suggests that moderately massive dark halos surround bright spiral galaxies. The relative velocities of the galaxies in binary systems were found to decrease with increasing relative luminosity of the satellite. We obtained evidence that the Tully-Fisher relation for binary members could be flatter than that for local field galaxies. An enhanced star formation rate in the binary members may be responsible for this effect. In most binary systems, the direction of the orbital motion of the satellite coincides with the direction of the rotation of the main galaxy. Seven candidates for distant M 51-type objects were found in the Northern and Southern Hubble Deep Fields. A comparison of this number with the statistics of nearby galaxies provides evidence for the rapid evolution of the space density of M 51-type galaxies with redshift z. We assume that M 51-type binary systems could be formed through the capture of a satellite by a massive spiral galaxy. It is also possible that the main galaxy and its satellite in some of the systems have a common cosmological origin. (C) 2003 MAIK "Nauka/Interperiodica".

Язык оригиналаАнглийский
Страницы (с-по)429-436
Число страниц8
ЖурналAstronomy Letters
Том29
Номер выпуска7
DOI
СостояниеОпубликовано - июл 2003

ID: 32201504