An improved map of the Galactic Faraday sky (Oppermann et al.)

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/