Bar charts showing the results of fitting 1–5 Gaussian components to the PDF of the sources 0014+813, 0059+581, 1739+522, and 1334−127 plotted in Fig. 4. The number of components adjusted is given beneath each gray bar. The height of each bar indicates the total integral value obtained for the corresponding fit. The arrows show the orientation of the resulting preferred directions and the associated uncertainty (represented as a cone around each arrow). The vertical position of the arrows reflects the contribution of the corresponding Gaussian component to the total integral. See Table 1 for the full parameter values.