The galactic magnetic field

Ronnie Jansson, Glennys R. Farrar

    Research output: Contribution to journalArticlepeer-review


    With this Letter, we complete our model of the Galactic magnetic field (GMF), by using the WMAP7 22 GHz total synchrotron intensity map and our earlier results to obtain a 13-parameter model of the Galactic random field, and to determine the strength of the striated random field. In combination with our 22-parameter description of the regular GMF, we obtain a very good fit to more than 40,000 extragalactic Faraday rotation measures and the WMAP7 22 GHz polarized and total intensity synchrotron emission maps. The data call for a striated component to the random field whose orientation is aligned with the regular field, having zero mean and rms strength ≈20% larger than the regular field. A noteworthy feature of the new model is that the regular field has a significant out-of-plane component, which had not been considered earlier. The new GMF model gives a much better description of the totality of data than previous models in the literature.

    Original languageEnglish (US)
    Article numberL11
    JournalAstrophysical Journal Letters
    Issue number1
    StatePublished - Dec 10 2012


    • cosmic rays -Galaxy: general - ISM: magnetic fields - magnetic fields Online-only material: color figures

    ASJC Scopus subject areas

    • Astronomy and Astrophysics
    • Space and Planetary Science


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