Analysis of the scintillation pattern of the pulsar PSR B0329+54 based on VLBI data at 1650 MHz

The velocity of motion of the diffraction pattern of the pulsar PSR B0329+54 at 1.6 GHz has been measured. Using a specialized method for the amplitude calibration of the VLBI data, scintillation curves were obtained for the ten ground antennas that took part in the experiment jointly with the orbiting antenna HALCA. The session lasted 12 hours. Our analysis shows that the pulsar has two timescales, 20 and 1 min. The velocity of the scintillation pattern was determined by measuring the shift of the maximum of the scintillation-curve cross-correlation function relative to zero. It turned out that the scintillation spots move independently from each other: there is no ordered motion of the diffraction pattern as a whole. The measured drift velocities are from 25 to 40 km/s; the average magnitude of the drift velocity is 39-15 km/s, whereas the magnitude precalculated from the pulsar proper motion taking into account the Earth's motion around the Sun and the Sun's motion with respect to the Local Standard of Rest is 122 km/s. A thin-screen model is unable to provide an adequate description of this behavior.