2005/09/24 by V. Reshetnikov, F. Bournaud, F. Combes +3 · 1 citation
Physics and Astronomy · #Astrophysics and Star Formation Studies #Galaxies: Formation, Evolution, Phenomena #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1051/0004-6361:20041728
Accepted for publication in A&A
arxiv created 2005/09/24 · openalex publication_date 2006/01/13 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/31
We have observed the emission-line kinematics and photometry of a southern triplet of galaxies. The triplet contains a giant spiral galaxy AM 1934-563 which optical structure resembles a polar-ring galaxy: distorted spiral disk, seen almost edge-on, and a faint large-scale (45 kpc in diameter) warped structure, inclined by 60o-70o with respect to the disk major axis. The triplet shows relatively small velocity dispersion (69 km/s) and a large crossing time (0.17 in units of the Hubble time). The disk of AM 1934-563 demonstrates optical colors typical for an early-type spirals, strong radial color gradient, and almost exponential surface brightness distribution with an exponential scale-length value of 3.1 kpc (R passband). The galaxy shows a maximum rotation velocity of about 200 km/s and it lies close to the Tully-Fisher relation for spiral galaxies. The suspected polar ring is faint (μ(B) > 24) and strongly warped. Its total luminosity comprises (10-15)% of the total luminosity of AM 1934-563. We then try to model this system using numerical simulations, and study its possible formation mechanisms. We find that the most robust model, that reproduces the observed characteristics of the ring and the host galaxy, is the tidal transfer of mass from a massive gas-rich donor galaxy to the polar ring. The physical properties of the triplet of galaxies are in agreement with this scenario.