5 Concluding remarks

 

The maps shown include information on a wealth of faint emission structures at medium Galactic latitudes. The total intensities decrease quickly with increasing distance from the plane as is expected for a thin disk of emission. Strong sources become rare, but faint extended ridges, arcs and more or less structured discrete emission regions are seen superimposed on the still dominating unresolved Galactic emission.

There is substantial diffuse polarized emission seen in all the observed fields. This emission is characterized by fluctuations on angular scales of the beam size up to several degrees. Interestingly, there exist significantly polarized regions of the order of several degrees in size, which have no corresponding structures in the total-power emission. Moreover, within the polarized emission there are numerous nearly straight, loop or arc shaped structures, which seem to be depolarized. They are most pronounced in the direction of the Galactic anticentre, where the line of sight across the Galaxy is comparably short. In these regions, the total intensity of diffuse Galactic emission as revealed from the Stockert 1.4 GHz survey is less than 0.5 K. In view of the observed polarized intensities of up to 0.25 K, there are also areas with well organized magnetic fields and quite small Faraday rotation effects. The most likely explanation for the small-scale structures are significant spatial variations of the Faraday rotation by the interstellar medium in the line of sight, which modulate a significantly polarized smooth Galactic diffuse emission. It is not clear whether fluctuations of the Galactic magnetic field or changes in the electron density are the reason for that. We conclude that probing the properties of the diffuse Galactic emission via a polarization survey is a promising tool towards the improvement of our current understanding of the Galaxy and the local ISM.