VLBI Polarimetric Research

We present the multi-frequency VLBI polarimetric observations of a QSO NRAO 530. This thesis introduces the origin of radio polarimetric research, its development, the theoretical model and its contribution to the radio astronomy. We discuss the observations and data reductions of the VLBA polarimetric observations. Using the multi-frequency VLBA polarimetric data in 1997 and the -43 GHz data in 1999, we discuss the dynamical properties, VLBI components' spectra and physical properties, the magnetic field structure and directions, even their formation. There are six chapters as follows.In the first chapter we review the radio polarimetric researches which began in 1970s as well as VLBA polarimetric observations. By VLBI polarimetric researches we can know about the magnetic field structure and direction. Multi-frequency polarization observations are used to study the Faraday rotation; multi-epoch multi-frequency polarization observations will present us the evolution of the magnetic field, and by the combinations of VLBI components spectra and the jet dynamical properties we can probe the AGN jet composition. The above study fields come to be easier with the employment of VLBA.In the second chapter we introduce the origin of radio polarization radiations, the Faraday rotation during its transfer, and the shock model in the jets.Chapter three mainly discusses the VLBI polarimetric observations, the errors introduced by the feed polarization calibration and the error analyses. By the introduction of theoretical models we give some basic concepts in the polarization research: fraction of linear polarization, fraction of circular polarization, Stokes parameters, parallactic angle, electric vector position angle (EVPA) .The first three chapters concentrate on the basic knowledges, from chapter 4 we will give the VLBA polarimetric data reductions in detail, which contain theory, parameters selection and attention in each step of calibration, and how to check up calibrations. There are several steps in the VLBI polarimetric data calibrations: amplitude, bandpass, parallactic angle, phase (phase, delay, delay rate and R-L phase delay), self-calibration, feed-D and EVPA. The polarimetric calibrations of parallactic angle, R-L phase delay, feed-D and EVPAs are different from total density data reductions. In the calibration of feed-D according to the "similarity assumption" we...