Depolarisation and the study of galaxy cluster magnetic fields with the SKA

M. Krause, P. Alexander, R. Bolton

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Future radio surveys, most notably with the SKA aim at determining the comological evolution of magnetic fields using Faraday rotation of a huge number of cosmological radio sources. In contrast to currently used techniques, these surveys are planned for sub-GHz radio frequencies. However, radio emission is typically depolarised at low frequencies due to differential Faraday
rotation along different lines of sight within the telescope beam. Therefore, it is vital for the experiment to predict the exact frequency below which we expect depolarisation to occur. We compare a new turbulent depolarisation model to the classical two-field case, finding many interesting similarities. We calculate the depolarisation frequency, below which magnetic field measurements become much more difficult for the new model. Extrapolating from recent data,
we find a median depolarisation frequency of 300 MHz for typical SKA sources, hence enabling the determination of magnetic fields via the SKA mid frequency band.
Original languageUndefined/Unknown
Title of host publicationProceedings of Science Conference Proceedings
Subtitle of host publicationFrom Planets to Dark Energy: the Modern Radio Universe
PublisherProceedings of Science (PoS)
Publication statusPublished - 2007
EventProceedings of Science: From Planets to Dark Energy: the Modern Radio Universe - University of Manchester, Manchester, United Kingdom
Duration: 1 Oct 20075 Oct 2007


ConferenceProceedings of Science
Country/TerritoryUnited Kingdom
Internet address

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