Features of the local galactic magnetic field

The propagation of cosmic ray nuclei in the Galaxy is strongly affected by the galactic magnetic field, and the derivation of information about the cosmic ray electron component, from studies of the synchrotron radiation, also requires a knowledge of the magnetic field. Inevitably knowledge is scanty but pulsar rotation measures hold out the prospect of improvement, and the authors discuss this, with particular reference being made to the 'local' region of the Galaxy; within about 1.5 kpc of the Sun. The results confirm the existence of an extragalactic component of cosmic ray nuclei above 10 19 eV, and at much lower energies, approximately=10 9 eV, allow a good understanding of the propagation of the galactic electron component.