ANISOTROPIC RADIO AND OPTICAL-EMISSION IN THE SEYFERT NUCLEUS OF NGC-3227

We present a high-sensitivity study of the photoionized and relativistic plasma associated with the Seyfert nucleus of NGC 3227. [O III] 5007-Angstrom images of the high-excitation ionized gas show an asymmetric distribution extending similar to 7 arcsec to the north-east (NE) of the optical continuum nucleus. The axis of symmetry of the [O III] 5007-Angstrom structure is along PA similar to 30 degrees, and could be consistent with photoionization by a cone of UV continuum from the nucleus. Long-slit spectroscopy shows that the [O III] 5007-Angstrom emitting gas has relatively broad lines (similar to 250 km s(-1)) typical of a 'narrow-line region' rather than an 'extended narrow-line region'. MERLIN images at wavelengths of 6 and 18 cm reveal a 0.4-arcsec double radio source. The PA of the double is similar to - 10 degrees and hence does not align with the symmetry axis of the [O III] 5007-Angstrom structure. We consider a number of mechanisms to account for this misalignment, ranging from the effect of 'density bounding' of collimated UV emission, to the possibility that the ionized gas is flowing out from the nucleus, along a density gradient, in a different direction from the radio collimation. We tentatively conclude that NGC 3227 may represent a case in which the radio structure and [O III] 5007-Angstrom gas are physically misaligned.