METER-WAVELENGTH OBSERVATIONS OF PULSARS USING VERY-LONG-BASELINE INTERFEROMETRY

摘要

This thesis presents the results of an investigation of the angular structure imposed on pulsar radiation due to scattering in the interstellar medium. The technique of very-long-baseline interferometry (VLBI) was used to obtain the necessary high angular resolution (~0,1 arcsec). The interferometers formed by the Arecibo (305 m), NRAO (92 m), and Sugar Grove (46 m) telescopes were used at radio frequencies of 196, 111, and 74 MHz during seven separate observing sessions between 1971 November and 1973 February. The observations were concentrated on the Crab nebula pulsar (PSR 0531+21), and several strong, low-dispersion pulsars were also observed.nA crude visibility function for the Crab nebular pulsar was obtained during a 144-MHz VLBI experiment in 1971 March. The visibility function is consistent with a Gaussian brightness distribution having a half-power diameter of 0.05+0.03 arcsec.