The galactic magnetic field

Ronnie Jansson, Glennys R. Farrar

    Research output: Contribution to journalArticle


    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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