Polarimetry of External Galaxies

This review presents results to date on the wavelength dependence of interstellar polarization (ISP) in other galaxies. A number of different techniques are discussed, and galaxy types range from those similar to the Milky Way Galaxy through to high-redshift radio galaxies. Although data are both sparse and generally limited in wavelength coverage, it appears that the ISP curves are similar to those in the Galaxy, indicating that the properties of dust grains responsible for producing the ISP vary little between different galaxy types. The advantages of using radio polarization maps to determine the magnetic field structure in galaxies is emphasized.