GLOBAL SIMULATIONS OF MAGNETOROTATIONAL INSTABILITY IN THE COLLAPSED CORE OF A MASSIVE STAR

Journal Article · Thu Jun 20 04:00:00 EDT 2013 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/770/2/L19· OSTI ID:22118775

Sawai, H.; Yamada, S. ^[1]

---

1. Waseda University, Shinjuku, Tokyo 169-8555 (Japan)

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.

• OSTI ID: 22118775
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 2 Vol. 770; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
APPROXIMATIONS
ASTRONOMY
ASTROPHYSICS
AXIAL SYMMETRY
COMPARATIVE EVALUATIONS
COMPUTERIZED SIMULATION
DIFFUSION
INSTABILITY
MAGNETIC FIELDS
MAGNETOHYDRODYNAMICS
NEUTRON STARS
SPATIAL RESOLUTION
SUPERNOVAE
TURBULENCE