| Sammanfattning: | The structure of magnetic fields in galaxies remains poorly constrained, despite the importance of magnetism
in the evolution of galaxies. Radio synchrotron and far-infrared (FIR) polarization and polarimetric observations
are the best methods to measure galactic scale properties of magnetic fields in galaxies beyond the Milky
Way. We use synthetic polarimetric observations of a simulated galaxy to identify and quantify the regions,
scales, and interstellar medium (ISM) phases probed at FIR and radio wavelengths. Our studied suite of
magnetohydrodynamical cosmological zoom-in simulations features high-resolutions (10 pc full-cell size) and
multiple magnetization models. Our synthetic observations have a striking resemblance to those of observed
galaxies. We find that the total and polarized radio emission extends to approximately double the altitude above
the galactic disk (half-intensity disk thickness of ℎI radio ∼ ℎPI radio = 0.23±0.03 kpc) relative to the total FIR and
polarized emission that are concentrated in the disk midplane (ℎI FIR ∼ ℎPI FIR = 0.11±0.01 kpc). Radio emission
traces magnetic fields at scales of ≳ 300 pc, whereas FIR emission probes magnetic fields at the smallest scales
of our simulations. These scales are comparable to our spatial resolution and well below the spatial resolution
(< 300 pc) of existing FIR polarimetric measurements. Finally, we confirm that synchrotron emission traces a
combination of the warm neutral and cold neutral gas phases, whereas FIR emission follows the densest gas in
the cold neutral phase in the simulation. These results are independent of the ISM magnetic field strength. The
complementarity we measure between radio and FIR wavelengths motivates future multiwavelength polarimetric
observations to advance our knowledge of extragalactic magnetism.
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