Magnetic fields in the galactic Universe, as observed in supershells, galaxies, intergalactic and cosmic realms

Here I present a survey of magnetic fields in large objects, from the interstellar supershells (10 pc) up to the edge of the Universe (near a redshift z of 10), with an emphasis on discoveries made in the last decade, be they through particle astronomy or electromagnetic astronomy. For each type of object, the basic observational properties are summarized, and the best theoretical scenario which accounts for the large body of observations is discussed. The strength of these large-scale fields can vary from mGauss to mu Gauss. Magnetism acts as a tracer of the dynamical histories of cosmological and intracluster events, it guides the motion of the interstellar ionised gas, and it aligns the charged dust particles. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.