http://arxiv.org/abs/1401.4152
Wide-band radio polarization observations offer the possibility to recover information about the magnetic fields in synchrotron sources, such as details of their three dimensional configuration, that has previously been inaccessible. The key physical process involved is the Faraday rotation of the polarized emission in the source (and elsewhere along its propagation path). In order to proceed reliable methods are required for inverting the signals observed in wavelength space into useful data in Faraday space, with robust estimates of their uncertainty. In this paper we examine how variations of the intrinsic angle of polarized emission chi0 with the Faraday depth phi within a source affect the observable quantities. Using simple models for the Faraday dispersion F(phi) and chi0(phi), along with the current and planned properties of the main radio interferometers, we demonstrate how degeneracies among the parameters describing the magneto-ionic medium can be minimised by combining observations in different wavebands. In particular we show that it may be possible to recover the sign (and maybe even the magnitude) of the helicity of the magnetic field.
Fri, 17 Jan 14
35/53
You must be logged in to post a comment.