Magnetic fields in elliptical galaxies: using the Laing–Garrington effect in radio galaxies and polarized emission from background radio sources

ABSTRACT Magnetic fields in elliptical galaxies are poorly constrained because of a lack significant synchrotron emission from them. In this paper, we explore the properties magnetic ellipticals using two methods. First, exploit Laing–Garrington effect (asymmetry observed polarization fraction between radio galaxy jets) for 57 with redshifts up to 0.5. We use differences and rotation measure jet counterjet estimate small- large-scale around (including their circumgalactic medium). find that small-scale field (at scales smaller than driving scale turbulence, approximately 300 pc) lies range 0.1–2.75 $\mu{\rm G}$. The 100 kpc) is an order magnitude field. second method, cross-match Faraday measures (RMs) few hundred (out 3098) extragalactic sources catalogues number morphology intervening on RM distribution. both Gaussian non-Gaussian functions describe distribution derive its statistical properties. Finally, difference spirals ellipticals, at centre be ∼6 Both methods different observations analysis techniques give strengths consistent previous studies (≤10 G}$). results can used constrain dynamo theories evolution simulations.