EDP Sciences

Vol. 542
In section 5. Galactic structure, stellar clusters and populations

An improved map of the Galactic Faraday sky

by N. Oppermann, H. Junklewitz, G. Robbers, et al., A&A 542, A93

The paper presents a comprehensive combination of existing large-scale Faraday rotation surveys, which comprise more than 41000 individual measurements. The authors use a novel filtering algorithm to produce an all-sky map of the Galactic line-of-sight magnetic field structure - and its uncertainty - with a resolution of about 0.5 degree. The large-scale structure of the Galactic magnetic field is fundamental for constraining any dynamo models and, for example, for modeling cosmic ray propagation. It is also a good basis for a comparison with extragalatic fields and for comparisons with the Planck and Fermi/LAT all-sky maps of the Galaxy. The authors discuss the separation of local and large-scale structures, identifying several large-scale shells and arcs on the basis of their Faraday depths. Additional characterizations include the quadratic structure function and power spectrum. The data are available in interactive form through http://www.mpa-garching.mpg.de/ift/faraday/