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Galactic magnetic fields, from radio polarimetry of the WIM

M. Haverkorn·P. Katgert·A. G. de Bruyn·F. Heitsch
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Abstract

Multi-frequency radio polarimetry of the diffuse Galactic synchrotron background gives new viewpoints on the Galactic magnetic field. Rotation measure maps reveal magnetic structures on arcminute to degree scales, such as a ring in polarization that we interpret as a magnetic tunnel. A complication using this technique is depolarization across the beam and along the line of sight. The influence of beam depolarization has been estimated using numerical models of the magneto-ionic ISM, through which polarized radiation propagates. The models show that depolarization canals similar to those observed can be caused by beam depolarization, and that the one-dimensional gradients in RM needed to produce these canals are ubiquitous in the medium.

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M. Haverkorn, P. Katgert, A. G. de Bruyn, F. Heitsch. 2003-10-05. Galactic magnetic fields, from radio polarimetry of the WIM. https://doi.org/10.1007/1-4020-2620-x_62

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