Core-collapse supernovae with nonuniform magnetic fields

Hidetomo Sawai, Kei Kotake, Shoichi Yamada

    Research output: Contribution to journalArticle

    52 Citations (Scopus)

    Abstract

    We perform two-dimensional numerical simulations on the core collapse of a massive star with strong magnetic fields and differential rotations using the numerical code ZEUS-2D. Changing field configurations and laws of differential rotation parametrically, we compute 14 models and investigate the effects of these parameters on the dynamics. In our models we do not solve the neutrino transport but instead employ a phenomenological parametric EOS that takes into account the neutrino emissions. As a result of the calculations, we find that the field configuration plays a significant role in the dynamics of the core if the initial magnetic field is large enough. Models with initially concentrated fields produce more energetic explosions and more prolate shock waves than the uniform field. Quadrupole-like fields produce a remarkably collimated and fast jet, which might be important for gamma-ray bursts (GRBs). The Lorentz forces exerted in the region where the plasma β is less than unity are responsible for these dynamics. The pure toroidal field, on the other hand, does not lead to any explosion or matter ejection. This suggests that the presupernova models, in which toroidal fields are predominant are disadvantageous for the magnetorotation-induced supernova considered here. Models with initially weak magnetic fields do not lead to explosion or matter ejection, either. In these models magnetic fields play no role, as they do not grow on the timescale considered in this paper and the magnetic pressure could be comparable to the matter pressure. This is because the exponential field growth as expected in MRI is not seen in our models. The magnetic field is amplified mainly by field compression and field wrapping in our simulations.

    Original languageEnglish
    Pages (from-to)446-455
    Number of pages10
    JournalAstrophysical Journal
    Volume631
    Issue number1 I
    DOIs
    Publication statusPublished - 2005 Sep 20

    Fingerprint

    nonuniform magnetic fields
    supernovae
    magnetic field
    toroidal field
    explosions
    explosion
    magnetic fields
    ejection
    neutrinos
    Lorentz force
    EOS
    configurations
    shock wave
    massive stars
    gamma ray bursts
    simulation
    shock waves
    unity
    energetics
    quadrupoles

    ASJC Scopus subject areas

    • Space and Planetary Science

    Cite this

    Core-collapse supernovae with nonuniform magnetic fields. / Sawai, Hidetomo; Kotake, Kei; Yamada, Shoichi.

    In: Astrophysical Journal, Vol. 631, No. 1 I, 20.09.2005, p. 446-455.

    Research output: Contribution to journalArticle

    Sawai, Hidetomo ; Kotake, Kei ; Yamada, Shoichi. / Core-collapse supernovae with nonuniform magnetic fields. In: Astrophysical Journal. 2005 ; Vol. 631, No. 1 I. pp. 446-455.
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