A high star formation rate (SFR) in the disk of spiral galaxies usually leads to strong radio emission and to a high total magnetic field strength. Observations of edge-on galaxies show, on the other hand, that the vertical scale height of the radio emission is very similar in galaxies of different Hubble types and different global SFR. This implies that the bulk velocity of the cosmic rays CR (the galactic wind velocity) is determined by the total field strength within the galactic disk.
The galaxies in our sample also show a similar large-scale magnetic field configuration, parallel to the midplane and X-shaped further away from the disk plane, independent of Hubble type and SFR. It turned out that the SFR in the disk neither increases the generated large-scale magnetic field strength nor changes its pattern, whereas a CR driven galactic wind may influence the galactic dynamo action in a way to generate such a magnetic field structure. The galactic wind may even solve the problem of helicity conservation of dynamo action.