A 4.5σ excess RM dispersion of 4.13 ± 0.91 rad m^{-2} is found in 191 Mg II sightlines versus controls, implying model-dependent CGM magnetic fields of 0.4-0.8 μG at projected radii 20-150 kpc and z~1.14.
Detection of microgauss coherent magnetic fields in a galaxy five billion years ago
3 Pith papers cite this work. Polarity classification is still indexing.
abstract
Magnetic fields play a pivotal role in the physics of interstellar medium in galaxies, but there are few observational constraints on how they evolve across cosmic time. Spatially resolved synchrotron polarization maps at radio wavelengths reveal well-ordered large-scale magnetic fields in nearby galaxies that are believed to grow from a seed field via a dynamo effect. To directly test and characterize this theory requires magnetic field strength and geometry measurements in cosmologically distant galaxies, which are challenging to obtain due to the limited sensitivity and angular resolution of current radio telescopes. Here, we report the cleanest measurements yet of magnetic fields in a galaxy beyond the local volume, free of the systematics traditional techniques would encounter. By exploiting the scenario where the polarized radio emission from a background source is gravitationally lensed by a foreground galaxy at z = 0.439 using broadband radio polarization data, we detected coherent $\mu$G magnetic fields in the lensing disk galaxy as seen 4.6 Gyrs ago, with similar strength and geometry to local volume galaxies. This is the highest redshift galaxy whose observed coherent magnetic field property is compatible with a mean-field dynamo origin.
years
2026 3verdicts
UNVERDICTED 3representative citing papers
Reports results from two searches for new radio lenses in existing surveys and discusses the completeness of the population usable for constraining dark matter properties via astrometric perturbations.
FRBs serve as cosmological probes via dispersion measure, scattering, and Faraday rotation to constrain baryon distribution, expansion history, magnetic fields, and fundamental physics effects.
citing papers explorer
-
Magnetised CGM Gas at z~1 revealed by SPICE-RACS
A 4.5σ excess RM dispersion of 4.13 ± 0.91 rad m^{-2} is found in 191 Mg II sightlines versus controls, implying model-dependent CGM magnetic fields of 0.4-0.8 μG at projected radii 20-150 kpc and z~1.14.
-
Taking Inventory of the Most Promising Lensed Radio Sources for Constraining Fundamental Properties of Dark Matter
Reports results from two searches for new radio lenses in existing surveys and discusses the completeness of the population usable for constraining dark matter properties via astrometric perturbations.
-
Fast Radio Bursts as Cosmological Probes
FRBs serve as cosmological probes via dispersion measure, scattering, and Faraday rotation to constrain baryon distribution, expansion history, magnetic fields, and fundamental physics effects.