List of Figures

1. Cygnus-A
2. The manifestation of three types of polarization
3. Diagram of the Faraday effect
4. Spectra of eight types of AGN
5. Two images where the jets of the radio sources can be seen. On the left side an image of Radio Galaxy Cygnus A and on the right side the Quasar 3C175 taken from the 3C catalogue of Alan Bridle.
6. Sketch of the source and a magneto-ionic medium around the source demonstrating the Faraday screen which can cause the depolarization asymmetry. D is the diameter of the screen, a the radius and $\theta$ the angle to the line of sight.
7. Total intensity contour plot by Jägers et al. 1981.
8. An example uv-plot of an observation of 4C34.47 taken with L-band B-array. X-axis is the baseline length (in kilo$\lambda$), Y-axis is the flux (in Jansky's).
9. Contour plots of the four images. The contour levels are RMS (table (5)) times 3, 6, 9, 12, 18, 24, 48, 96, 192 mJy Beam$^{-1}$. The first contour represents 3$\sigma$ detection. From top left to bottom right: High resolution 20cm image (A1), Low resolution 20cm image (A3), High resolution 6cm image (A4), Low resolution 6cm image (C12).
10. Combined 1.4 GHz image of two different resolution maps, A1 (see figure (9a)) and A3 (see figure (9b)). The FWHM of the clean beam is 5.72 x 4.84 in arcseconds. Contour levels are 0.15 * 4, 6, 8, 10, 12, 14, 16, 18, 20, 25, 30, 40, 80, 160, 320 mJy/Beam.
11. Combined 5 GHz image of two different resolution maps, A4 (see figure (9c)) and C12 (see figure (9d)). The FWHM of the clean beam is 7.94 x 7.54 in arcseconds. Contour levels are 0.109 * 4, 6, 8, 10, 12, 14, 16, 18, 20, 25, 30, 40, 80, 160, 320 mJy/Beam.
12. Radio contours of 6 cm total intensity map of 3C 47 plotted over a greyscale of the depolarization ratio made by Fernini (1991).
13. Gray scale representation of the spectral index between 1.4 GHz and 5 GHz with superimposed contours of total intensity.
14. Contour map of the total intensity with polarization intensity and E-vectors overlaid at different frequencies. (a) 1452.4 MHz (b) 1502.4 MHz (c) 4885.1 MHz (d) 4835.1 MHz.
15. Contour map of the total intensity with linear polarization degree and E-vectors overlaid at different frequencies. (a) 1452.4 MHz (b) 1502.4 MHz (c) 4885.1 MHz (d) 4835.1 MHz.
16. Total intensity contour maps of north and south side of both IFs of A4, with linear polarization degree and E-vectors overlaid. (a) North lobe at 4872.6 MHz (b) North lobe at 4822.6 MHz (c) South jet + lobe at 4872.6 MHz (d) South jet + lobe at 4822.6 MHz.
17. Polarization intensity and angle plotted over a contour map of the southern hot spot of observation A3. Intermediate frequency at 1.4524 GHz.
18. Polarization intensity and angle plotted over a contour map of the southern hot spot of observation A3. Intermediate frequency at 1.5024 GHz. Note the small rotation with respect to the other 20 cm IF (figure 17).
19. Polarization intensity and angle plotted over a contour map of the southern hot spot of observation A4. Intermediate frequency at 4.8726 GHz.
20. Polarization intensity and angle plotted over a contour map of the southern hot spot of observation A4. Intermediate frequency at 4.8226 GHz. The 6 cm rotation difference is substantially smaller then at 20 cm.
21. Histogram plots of circular polarization of 4C34.47. Plot (a) shows the V-polarization of 1452.4 MHz image and (b) of the 4885.1 MHz image.
22. Dependence of the jet velocity to the angle at a flux ratio of S$_{j}$/S$_{cj}$=24
23. Dependence of the flux ratio of S$_{j}$/S$_{cj}$ versus the angle at a relativistic speed of 0.9c