Study On The Jet Motion In Radio Loud AGNs

In this thesis, we have summarized the basic properties, major characteristics, the results of new observations and theoretical studies about the active galactic nuclei (AGNs). Especially, we detailed review the special sub-class of AGNs-blazar, and focus on observational properties and the theoretical model of blazars. The thesis also summarizes the general understanding, some studies and new results of research of AGNs during my master term.In observations, the radio knots of TeV blazar move very slowly at the VLBI scale contrast to other gamma ray sources. But their violent variations required for similar Lorentz factors. There are several models to explain this. In order to check up the model, we collected a sample of VLBI radio knots of radio loud AGNs to study their motions statistically.Our main works and results are as follow: (1) Aiming at the data of 108 blazars we studied the relations between the location of the biggest velocity of each knot and the radio luminosity, and the relations between radio knots' motions and the distance from the core. The result shows the tendency that the accelerated region decreasing with decreasing luminosity. It is probably that the jet has decelerated in VLBI scale in TeV blazars, and agrees well with decelerating model of jet. (2) The radio galaxies move very slowly possibly due to large angles between the jet axis and the line of sight.We collected the VLBI data from observations and studied the essential process of blazar in theory, and explained the different jet motions statistically.