Jet directions in Seyfert galaxies

Here 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 selecte d from a mostly isotropic property, the 60 mu m flux, and warm infrared col ors. We used VLA A-array 3.6 cm continuum data and ground-based optical ima ging, homogeneously observed and reduced to minimize selection effects. For parts of the analysis we enlarged the sample by including galaxies serendi pitously selected from the literature. For each galaxy we have a pair of po ints (i, delta), which are the inclination of the galaxy relative to the li ne of sight and the angle between the jet projected into the plane of the s ky and the host galaxy major axis, respectively. For some galaxies we also had information about which side of the minor axis is closer to Earth. This data is combined with a statistical technique, developed by us, to determi ne the distribution of beta angles in three dimensions,, the angle between the jet and the host galaxy plane axis. We found from an initial analysis o f the data of the 60 mu m sample, where Seyfert 1 and 2 galaxies were not d ifferentiated, that the observed distribution of i and delta values can be well represented either by a homogeneous sin beta distribution in the range 0 degrees less than or equal to beta less than or equal to 90 degrees or i n 0 degrees less than or equal to beta less than or equal to 65 degrees, bu t not by an equatorial ring. A more general model, which tested beta-distri butions in the range beta(1) less than or equal to beta less than or equal to beta(2), for different ranges of beta(1) and beta(2) values, required be ta(2) to be larger than 65 degrees and gave preference for beta(1) smaller than 40 degrees-50 degrees. An important result from our analysis was obtai ned when we determined whether the jet was projected against the near or th e far side of the galaxy and differentiated between Seyfert 1 and Seyfert 2 galaxies, which showed that the model could not represent Seyfert 1 galaxi es adequately. We found that the inclusion of viewing angle restrictions fo r Seyfert 1 galaxies, namely, that a galaxy can be recognized as a Seyfert 1 only if the angle between the jet and the line of sight (\phi\) is smalle r than a given angle phi(c) and that the galaxy inclination i is smaller th an an angle i(c), gave rise to statistically acceptable models. This indica tion that there is a difference in viewing angle to the central engine betw een Seyfert 1 galaxies and Seyfert 2 galaxies is a direct and independent c onfirmation of the underlying concepts of the unified model. We discuss pos sible explanations for the misalignment between the accretion disk and the host galaxy disk: warping of the accretion disk by self-irradiation instabi lity, by the Bardeen-Petterson effect, or by a misaligned gravitational pot ential of a nuclear star cluster surrounding the black hole, as well as fee ding of the accretion disk by a misaligned inflow of gas from minor mergers , capture of individual stars or gas from the nuclear star cluster, and the capture of individual molecular clouds from the host galaxy.