English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The new generation of low-frequency radio telescopes, such as the LowFrequency Array (LOFAR: a Square Kilometre Array-low pathfinder), providesadvancements in our capability of probing Galactic magnetism throughlow-frequency polarimetry. Maps of diffuse polarized radio emission and Faradayrotation can be used to infer properties of, and trace structure in, themagnetic fields in the ISM. However, to date very little of the sky has beenprobed at high angular and Faraday depth resolution. We observed a 5x5 degreeregion centred on the nearby galaxy IC342 using LOFAR in the frequency range115-178 MHz at 4 arcmin resolution and performed Faraday tomography to detectforeground Galactic polarized synchrotron emission separated by Faraday depth(different amounts of Faraday rotation). Our Faraday depth cube shows richpolarized structure, with up to 30 K of polarized emission at 150 MHz. Wedetect two overlapping diffuse polarized features that are clearly separated inFaraday depth. Faraday-thick structures at such low frequencies would be toostrongly depolarized to explain the observations and are therefore rejected.Only Faraday thin structures will not be strongly depolarized; producing suchstructures requires localized variations in the ratio of synchrotron emissivityto Faraday depth per unit distance, which can arise from several physicalphenomena, such as a transition between regions of ionized and neutral gas. Weconclude that the observed polarized emission is Faraday thin, and propose thatthe emission originates from two neutral clouds in the local ISM. We havemodeled the Faraday rotation for this line of sight and estimated that the lineof sight component of magnetic field of the local ISM for this direction variesbetween -0.86 and +0.12 uG. We propose that this may be a useful method formapping magnetic fields within the local ISM.

Faraday tomography of the local interstellar medium with LOFAR: Galactic foregrounds towards IC342