ABSTRACT

Here we summarize the main results derived from optical fiber observations (bidimensional spectroscopy) related to the kinematics of the circumnuclear region of NGC 5728. We present additional arguments supporting that the ‘true’ nucleus of this galaxy is displaced in velocity and space from the optical nucleus. In view of this result, the region of double-peaked emission line profiles is connected to the nucleus, and the red component probably represents outflowing gas.

INTRODUCTION

NGC 5728 is a spiral barred galaxy classified as Seyfert 2 (Véron-Cetty et al. 1982; Phillips et al. 1983), which shows some peculiar features in its circumnuclear environment. Here we can point out the presence of a region showing double-peaked emission line profiles in the vicinity of its nucleus, the asymmetric position (with respect to the optical nucleus) of a ring of blue stars and ionized gas (Rubin 1981; Schommer et al. 1988; Wagner and Appenzseller 1988), and the possible presence of a weak BLR misaligned with respect to the NEL maximum (Pecontal et al. 1990).

We have observed the circumnuclear region of NGC 5728 with a new observational arrangement based on the use of optical fibers (Arribas et al. 1991), which is similar to the one presented by Shapovalova (see Afanasiev and Shapovalova, these proceedings). The observations were performed on May 8, 1989, using the 4.2m WHT sited at the ORM. The detailed analysis and results on NGC 5728 can be found in Arribas and Mediavilla (1993).