Magnetic Field Amplification and Saturation by Turbulence in A Relativistic Shock Propagating through An Inhomogeneous Medium

We perform two-dimensional relativistic magnetohydrodynamic simulations of a mildly relativistic shock propagating through an inhomogeneous medium. We show that the postshock region becomes turbulent owing to preshock density inhomogeneity, and the magnetic field is strongly amplified due to the stretching and folding of field lines in the turbulent velocity field. The amplified magnetic field evolves into a filamentary structure in two-dimensional simulations. The magnetic energy spectrum is flatter than the Kolmogorov spectrum and indicates that the so-called small-scale dynamo is occurring in the postshock region. We also find that the amplitude of magnetic-field amplification depends on the direction of the mean preshock magnetic field.

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MAGNETIC FIELD AMPLIFICATION AND SATURATION BY TURBULENCE IN A RELATIVISTIC SHOCK PR

Gamma-ray Bursts: 15 Years of GRB Afterglows ◽

10.1051/978-2-7598-1002-4.c027 ◽

2020 ◽

pp. 173-176

Author(s):

Y. Mizuno ◽

M. Pohl ◽

J. Niemiec ◽

B. Zhang ◽

K. -I. Nishikawa ◽

...

Keyword(s):

Magnetic Field ◽

Relativistic Shock ◽

Field Amplification

Download Full-text

MAGNETIC FIELD AMPLIFICATION AND SATURATION BY TURBULENCE IN A RELATIVISTIC SHOCK PR

Gamma-ray Bursts: 15 Years of GRB Afterglows ◽

10.1051/978-2-7598-1002-4-027 ◽

2020 ◽

pp. 173-176

Author(s):

Y. Mizuno ◽

M. Pohl ◽

J. Niemiec ◽

B. Zhang ◽

K. -I. Nishikawa ◽

...

Keyword(s):

Magnetic Field ◽

Relativistic Shock ◽

Field Amplification

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Magnetic field amplification and saturation in turbulence behind a relativistic shock

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stu196 ◽

2014 ◽

Vol 439 (4) ◽

pp. 3490-3503 ◽

Cited By ~ 24

Author(s):

Yosuke Mizuno ◽

Martin Pohl ◽

Jacek Niemiec ◽

Bing Zhang ◽

Ken-Ichi Nishikawa ◽

...

Keyword(s):

Magnetic Field ◽

Relativistic Shock ◽

Field Amplification

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Magnetic field amplification in newly-born neutron stars

International Astronomical Union Colloquium ◽

10.1017/s0252921100042056 ◽

1996 ◽

Vol 160 ◽

pp. 435-436

Author(s):

H.-J. Wiebicke ◽

U. Geppert

Keyword(s):

Magnetic Field ◽

Neutron Stars ◽

Gravitational Collapse ◽

Dipole Field ◽

Numerical Calculations ◽

Selection Effects ◽

Thermoelectric Effects ◽

Field Amplification ◽

Seed Field ◽

Flux Conservation

AbstractWe present a scenario of magnetic field (MF) evolution of newly-born neutron stars (NSs). Numerical calculations show that in the hot phase of young NSs the MF can be amplified by thermoelectric effects, starting from a moderately strong seed-field. Therefore, there is no need to assume a 1012G dipole field immediately after the gravitational collapse of the supernova (SN) event. The widely accepted scenario for such a field to be produced by flux conservation during the collapse is critically discussed. Instead, it can be generated by amplification and selection effects in the first 104yrs, and by the subsequent fast ohmic decay of higher multipole components, when the NS cools down.

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