Magnetic deflections of ultra-high energy cosmic rays from Centaurus A

Azadeh Keivani, Glennys R. Farrar, Michael Sutherland

    Research output: Contribution to journalArticle

    Abstract

    We present the results of a study that simulates trajectories of ultra-high energy cosmic rays from Centaurus A to Earth, for particle rigidities from E/Z=2 EV to 100 EV, i.e., covering the possibility of primary particles as heavy as Fe nuclei with energies exceeding 50 EeV. The Galactic magnetic field is modeled using the recent work of Jansson and Farrar (JF12) which fitted its parameters to match extragalactic Faraday rotation measures and WMAP7 synchrotron emission maps. We include the random component of the GMF using the JF12 3D model for Brand(r→) and explore the impact of different random realizations, coherence length and other features on cosmic ray deflections. Gross aspects of the arrival direction distribution such as mean deflection and the RMS dispersion depend mainly on rigidity and differ relatively little from one realization to another. However different realizations exhibit non-trivial substructure whose specific features vary considerably from one realization to another, especially for lower rigidities. At the lowest rigidity of 2 EV, the distribution is broad enough that it might be compatible with a scenario in which Cen A is the principle source of all UHECRs. No attempt is made here to formulate a robust test of this possibility, although some challenges to such a scenario are noted.

    Original languageEnglish (US)
    Pages (from-to)47-55
    Number of pages9
    JournalAstroparticle Physics
    Volume61
    DOIs
    StatePublished - 2015

    Fingerprint

    rigidity
    deflection
    cosmic rays
    interstellar magnetic fields
    energy
    Faraday effect
    substructures
    arrivals
    synchrotrons
    coverings
    trajectories
    nuclei

    Keywords

    • Centaurus A
    • Galactic magnetic fields
    • Ultra-high energy cosmic rays

    ASJC Scopus subject areas

    • Astronomy and Astrophysics

    Cite this

    Magnetic deflections of ultra-high energy cosmic rays from Centaurus A. / Keivani, Azadeh; Farrar, Glennys R.; Sutherland, Michael.

    In: Astroparticle Physics, Vol. 61, 2015, p. 47-55.

    Research output: Contribution to journalArticle

    Keivani, Azadeh ; Farrar, Glennys R. ; Sutherland, Michael. / Magnetic deflections of ultra-high energy cosmic rays from Centaurus A. In: Astroparticle Physics. 2015 ; Vol. 61. pp. 47-55.
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