[O III] profile substructure in radio-quiet quasars

Abstract

Interactions between the radio jet and the optical emission of the narrow-line region (NLR) are a well known phenomenon in Seyfert galaxies. Here, we present the study of possible jet-NLR interactions in five radio-quiet PG quasars with double or triple radio structure. High spatial and spectral resolution observations were carried out in the Hβ-[O III] λ5007 wavelength range. In all cases, there is evidence for [O III] profile substructure (shoulders, subpeaks, blueshifted "broad" components) with different clarity. To measure the velocity, line width, intensity, and location of these [O III] components, several Gaussians were fitted. Often, the substructures are more pronounced close to the radio lobes, suggestive of jet-NLR interactions. Our observations support the unification scheme in which radio-quiet quasars are assumed to be the luminous cousins of Seyfert galaxies. © ESO 2006.