Tracing magnetic field with synchrotron polarization gradients: parameter study

Abstract

ABSTRACT We employ synthetic observations obtained with magnetohydrodynamic simulations to study how to trace the distribution of turbulent magnetic fields using the synchrotron polarization gradient techniques suggested by Lazarian & Yuen. Both synchrotron polarization gradients and its derivative gradients with regard to the squared wavelength λ2 are used to explore the probing ability of the technique in magnetic fields from sub- to super-Alfvénic turbulence. We focus on studies that involve multifrequency measurements in the presence of strong Faraday rotation and show the ways of how to recover the projected mean magnetic fields in the plane of the sky and the local magnetic fields within a tomographic slice. We conclude that the new techniques can successfully reconstruct the 3D magnetic field within our Milky Way and other galaxies. This paper opens an avenue for applying our new techniques to a large number of data cubes such as those from the Low-Frequency Array for radio astronomy and the Square Kilometre Array.