THE ISOLATED PAIR OF SPIRAL GALAXIES NGC-7469 IC-5283

We present a detailed analysis of the isolated pair of galaxies NGC 7469 and IC 5283. The data include Johnson B, V, and I and Ha CCD images, and long slit spectra along the major axes of the two galaxies. We notice that both members show clear signs of interaction. NGC 7469, a classical Seyfert 1 Sa galaxy, shows a very peculiar light distribution. The nucleus and the central regions are decentered with respect to the more external parts. The light profile could indicate the presence of a lens, but it is not well fitted by any combination of usually considered components. All the signs are those of a strongly perturbed galaxy. This can also be inferred from the rotation curve, which shows peculiarities in both its amplitude and shape. Besides its active nucleus, NGC 7469 harbors a very strong starburst in its central regions, mainly confined to a ring-like structure about 1 kpc from the center. The companion, IC 5283, a Scd galaxy, shows a knotty light distribution and a semidetached tidal tail, but its rotation curve looks rather normal. Different regions of star formation are delineated by the Ha emission all along the major axis direction. We argue that the differences shown by NGC 7469 and IC 5283 in the way they manifest the effects of the interaction are related to their morphology, which constraints the response of a system to a dynamical perturbation. The relation between morphology and nuclear activity in particular could reflect that kind of interplay.