Astronomy and Astrophysics – Astrophysics
Scientific paper
1997-04-04
Astronomy and Astrophysics
Astrophysics
latex, 10 pages, 5 figures, accepted for publication in the Astronomy and Astrophysics
Scientific paper
We present an analysis of structural features of all known galaxies with optical polar rings. We find a clear dichotomy for objects of this peculiar class. Bulge-dominated S0 galaxies possess only short narrow rings, while disk-dominated objects always have wide extended polar rings. We try by gas dynamical simulations to explain such a segregation by dependence of the ring-forming process on different galaxy potentials. It is found that the total mass captured into the ring during an encounter of a host-ring system with a gas-rich spiral galaxy of comparable mass exceeds 10^9 M_{\odot} (or about 10% of all gas in the donor galaxy), which is of the order of that found by observation. The process of gas to gather into a steady-state ring takes approximately (7 - 9) x 10^8 years. This time is somewhat shorter for rings forming around bulge-dominated galaxies. We also present observational arguments for S0 galaxies with extended rings to be similar to late-type spirals by their photometric properties, while numerical modelling of the extended ring formation suggests that these galaxies must possess massive dark halos as well. In this case, the sizes of the modelled rings turn out large enough (up to 30 kpc in diameter), and the time scale for ring formation is prolonged up to several Gyrs.
Reshetnikov Vladimir
Sotnikova Natalia
No associations
LandOfFree
Global structure and formation of polar-ring galaxies does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Global structure and formation of polar-ring galaxies, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Global structure and formation of polar-ring galaxies will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-108586