Jet directions in Seyfert galaxies

Abstract

We present the study of the relative angle between the accretion disk (or radio jet) and the galaxy disk for a sample of Seyfert galaxies selected from a mostly isotropic property, the 60$μ$m flux. For each galaxy we have a pair of points ($i$,$δ$), which are the inclination of the galaxy relative to the line of sight and the angle between the jet projected into the plane of the sky and the host galaxy major axis, respectively. This data is combined with a statistical technique to determine the distribution of $β$ angles {\it in 3 dimensions}, the angle between the jet and the host galaxy plane axis. The analysis of the data, not differentiating between Seyfert 1's and 2's, showed that the observed distribution of $i$ and $δ$ values can be well represented by a homogeneous $β-$distribution in the range $0^{\circ}\leqβ\leq90^{\circ}$. However, when we distinguished between Seyfert 1's and 2's, the models could not represent Seyfert 1's adequately. It was necessary to introduce viewing angle restrictions, that a galaxy can only be recognized as a Seyfert 1 if the angle between the jet and the line of sight ($|ϕ|$) is smaller than a given angle $ϕ_c$ and that the galaxy inclination $i$ is smaller than an angle $i_c$, in order to have statistically acceptable models. This is a direct and independent confirmation of the underlying concepts of the Unified Model. We discuss several ways to explain the misalignment between the accretion disk axis and the host galaxy disk axis.