Global simulations of magnetorotational instability in the collapsed core of a massive star

H. Sawai, Shoichi Yamada, H. Suzuki

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    35 Citations (Scopus)

    Abstract

    We performed the first global numerical simulations of magnetorotational instability from a sub-magnetar-class seed magnetic field in core-collapse supernovae. As a result of axisymmetric ideal MHD simulations, we found that the magnetic field is greatly amplified to magnetar-class strength. In the saturation phase, a substantial part of the core is dominated by turbulence, and the magnetic field possesses dominant large-scale components, comparable to the size of a proto-neutron star. A pattern of coherent channel flows, which generally appears during the exponential growth phase in previous local simulations, is not observed in our global simulations. While the approximate convergence in the exponential growth rate is attained by increasing spatial resolution, that of the saturation magnetic field is not achieved due to still large numerical diffusion. Although the effect of the magnetic field on the dynamics is found to be mild, a simulation with a high enough resolution might result in a larger impact.

    Original languageEnglish
    Article numberL19
    JournalAstrophysical Journal Letters
    Volume770
    Issue number2
    DOIs
    Publication statusPublished - 2013 Jun 20

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    Keywords

    • instabilities
    • magnetohydrodynamics (MHD)
    • methods: numerical
    • stars: magnetars
    • supernovae:general

    ASJC Scopus subject areas

    • Space and Planetary Science
    • Astronomy and Astrophysics

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