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 whose optical structure resembles a polar-ring galaxy: a distorted spiral disk, seen almost edge-on, and a faint large-scale (45 kpc in diameter) warped structure, inclined by 60• -70• with respect to the disk major axis. The triplet shows a relatively small velocity dispersion (69 km s −1 ) and a large crossing time (0.17 in units of the Hubble time). The disk of AM 1934-563 demonstrates optical colors typical of early-type spirals, a strong radial color gradient, and almost exponential surface brightness distribution with an exponential scalelength value of 3.1 kpc (R passband). The galaxy shows a maximum rotation velocity of about 200 km s −1 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 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.

Abstract. Surface photometry and a 21 cm H  line spectrum of the giant double-ringed galaxy ESO 474-G26 are presented.The morphology of this system is unique among the 30 000 galaxies with B ≤15. m 5. Two almost orthogonal optical rings with diameters of 60 and 40 kpc surround the central body (assuming H 0 = 70 km s −1 Mpc −1 ). The outer one is an equatorial ring, while the inner ring lies in a nearly polar plane. The rings have blue optical colors typical of late-type spirals. Both appear to be rotating around the central galaxy, so that this system can be considered as a kinematically confirmed polar ring galaxy. Its observational characteristics are typical of galaxy merger remnants. Although the central object has a surface brightness distribution typical of elliptical galaxies, it has a higher surface brightness for its effective radius than ordinary ellipticals. Possible origins of this galaxy are discussed and numerical simulations are presented that illustrate the formation of the two rings in the merging process of two spiral galaxies, in which the observed appearance of ESO 474-G26 appears to be a transient stage.

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A B S T R A C TWe report the results of spectroscopic observations of eight southern polar-ring galaxies (PRGs), in the wavelength range 5900±7300A: We find that five out of eight galaxies contain LINERs or Sy nuclei. Taking into consideration all PRGs with available spectral data, we estimate that about half of all PRGs and PRG candidates have either LINER or Seyfert nuclei. The observed widths of the [N ii]l 6583 line in the nuclei of early-type PRGs follow the linewidth±absolute luminosity relation for normal E/S0 galaxies. We found that one of the observed galaxies ± ESO 576-G69 ± is a new kinematically-confirmed polar-ring galaxy with a spiral host.

GMOS-IFU observational data were used to study the detailed two dimensional gas kinematics and morphological structures within the ∼ 500 × 421 pc 2 of the active Seyfert 2 galaxy NGC 4501. We provide empirical evidences of possible outflowing material from the central zones of NGC 4501 to the observer. In addition, we performed a spectral synthesis and diagnostic diagram analysis to determine respectively the dominant stellar population in the inner disc of this galaxy and to unveil the actual nature of the central engine of NGC 4501. The principal finding of this work is that the central regions of NGC 4501 are dominated by non circular motions connected to probable outflows of matter from the nuclear regions of this galaxy. A predominant old stellar population inhabits the internal zones of NGC 4501 excluding the possibility of ongoing starburst activity in the central parsecs of this galaxy. The latter result is confirmed by the diagnostic diagram analysis that establishes a preponderant active galactic nucleus character for NGC 4501. These outcomes together provide a general description of the gas motion and the corresponding nuclear activity in the internal disc of NGC 4501 in an attempt to elucidate the possible relation among the central activity and the induced kinematic properties of this nearby galaxy.