Rotation measure synthesis — A novel tool for discovering cosmic magnetic field

Modern broadband and multi-channel radiotéle-scopes' receivers allow to measure polarized flux from cosmic sources very densely sampled, in very broad frequency range. Such an equipment allows to study Faraday effects caused by — undetectable in emission — cosmic magnetic fields. The novel technique called Rotation Measure Synthesis can be used to reveal magnetized plasma e.g. in intergalactic space.