Magnetic Fields of Galaxies and Intergalactic Space

Abstract

After discussion of the solar and stellar magnetic fields we devote this chapter to the magnetism in the immense universe: in the Milky Way, extragalactic nebulae and intergalactic space. The main difference between magnetic fields of these two categories lies in the following. The Sun and magnetic stars have relatively strong fields in comparatively small volumes, while galaxies (including our Milky Way) and the intergalactic medium possess extremely faint fields in quite vast scopes. Therefore, the methods of measurements as well as the structure and characteristics of these two kinds of magnetic fields are to a great extent different.

In interstellar space, and in intergalactic space, electromagnetic phenomena may be of decisive importance. H. Alfvén and C.-G. Fälthammar, Cosmical Electrodynamics (1963).