The SHEVE observations of Pictor A were obtained and processed as described in chapter 2. Table 3.1 contains a summary of the observations.
Table: Observation log for PKS 0518-458.
Figure 3.1 shows the image of Pictor A obtained from the data of 1991 March 12, at 2.3 GHz. The source consists of a component which is extended toward the west at a position angle of approximately 
. Figure 3.2 is an image resulting from observations on 1993 February 18 with a similar array of telescopes but with a higher resolution due to the higher observing frequency of 8.4 GHz. The bright component apparent at the eastern end of the source, when Figures 3.1 and 3.2 are compared, can be identified as the flat-spectrum core. In addition a jet-like structure extends to the west at a position angle of 
.
Figure 3.3 is an image produced from the data of 1993 July 3, at 8.4 GHz, but with resolution higher than Figure 3.2 due to the longer baselines to Perth available in the array for this observation. The core is again the brightest feature in the image and the jet is well resolved, revealing an extension from the core at a position angle of approximately 
, with an angular length of approximately 7 mas, and a discrete component approximately 11 mas from the core, along the same position angle.
That the features in Figure 3.3 are real is supported by the fact that if the clean component model of Figure 3.3 is convolved with the restoring beam of Figure 3.2 then the reconvolved image and Figure 3.2 are identical.
The mismatch in frequency and resolution between the 2.3 GHz observations of 1991 March 12 and the 8.4 GHz observations in 1993 do not allow any meaningful investigation of evolution in the pc-scale radio source over this period. The comparison of 8.4 GHz data between the 4.5 months 1993 Feb 18 to 1993 Jul 3 indicates that no significant structural change could be detected on that time-scale.
The data on baselines to Hartebeesthoek at 1993 February 18 and 1993 July 3 were sparse and not used during the imaging process. However, a significant detection of the source was made on both occasions. Approximately 0.2 Jy were detected on the Tidbinbilla to Hartebeesthoek baseline on 1993 July 3, corresponding to an angular resolution of approximately 0.4 mas. Thus, a rough estimate of the radio core brightness temperature is 2 
K at 8.4 GHz.
One additional analysis of the data was made for the 2.3 GHz observations of 1991 March 12. During the correlation of the data, an attempt was made to correlate at the position of the radio hot spot in the western lobe since the hotspot was known to be compact at radio wavelengths, as seen in recent VLA images [Thompson, Crane, & MacKay 1995]. Fringes were detected at the position of the hot spot but it could not be ruled out that these fringes were simply side lobes in the delay beam as a result of the narrow bandwidth of the Mark II VLBI system.
Figure: Map peak, 0.8 Jy/beam. Contours, 0.5, 1, 2, 4, 8, 16, 32, and 64% of peak. Beam FWHM, 8.2 
3.3 mas @ 86 
.
Figure: Map peak, 1.0 Jy/beam. Contours, -0.5, 0.5, 1, 2, 4, 8, 16, 32, and 64% of peak. Beam FWHM, 24.5 9.7 mas @ -80 .
Figure: Map peak, 0.3 Jy/beam. Contours, -1, 1, 2, 4, 8, 16, 32, and 64% of peak. Beam FWHM, 1.9 1.6 mas @ -8.6 .
