THE GIANT NEBULAE ASSOCIATED WITH 3C-227 - EMISSION-LINE PROFILES ANDKINEMATIC MODELING

Detailed line profiles from the nebular gas surrounding the radio gala xy 3C 227 are presented. High-resolution spectroscopy around [O III] 4 959- and 5007-Angstrom emission lines, with an unprecedentedly high si gnal-to-noise ratio, reveals broad and asymmetric line profiles all ac ross the nebulae. The average width of the line complex is of the orde r of 100 km s(-1), with the mean peak position shifting from red to bl ue according to a general rotation pattern. The line profiles were fir st compared with the popular bicone models. However, even when extende d to include the effect of radial inflow or outflow, the bicone models fail to match the observed gas profiles. Instead, a ring model is pro posed, in which gas particles move in several nonintersecting circular orbits in force balance with the halo potential. The multiple-peaked line complexes seen at various positions in the nebula are then interp reted as the contribution of different rings projected in the same lin e of sight.