Apparent motion of quasars and its physical mechanisms

V.E.Zharov1 , M.V. Sazhin1, V.N. Semetsov1, K.V. Kuimov1, O.S. Sazhina1, N.T.Ashimbaeva1

1Sternberg Astronomical Institute, MSU, Moscow, Russia

Oral presentation  

We discuss the physical mechanisms of the apparent motion of the ICRF sources. The main features of these sources have shown to be divided into several groups with respect to their apparent motion. The motion of the first group of sources is linear and uniform. As far as the proper velocities of the radio sources are close to the speed of light and even exceed it in some cases, we naturally concluded that the radio sources are relativistic jets or plasma clouds moving with velocities closed to the speed of light. The linear and uniform motion has been explained by the model related with jet precession. The second group of sources demonstrate the non-uniform motion related with the acceleration processes of the matter in jets. The model of such sources is penetration into the jet of a compact cloud of matter which is accelerated by the jet up to the relativistic velocities. The third group of sources can be interpreted as an action of the two mechanisms: the acceleration of a cloud by moving matter of precessing jet. The fourth group of sources has shown to demonstrate the complicated motion, which is impossible to explain by the two discussed mechanism separately or joint. The interpretation of the last motions is the subject for future investigations. We choose the list of ICRF sources based on these models which will form the most stable coordinate system during several decades.