INVERSE CASCADE OF NONHELICAL MAGNETIC TURBULENCE IN A RELATIVISTIC FLUID

Journal Article · Mon Oct 20 00:00:00 EDT 2014 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/794/2/L26· OSTI ID:22364562

Zrake, Jonathan ^[1]

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1. Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Menlo Park, CA 94025 (United States)

The free decay of nonhelical relativistic magnetohydrodynamic turbulence is studied numerically, and found to exhibit cascading of magnetic energy toward large scales. Evolution of the magnetic energy spectrum P{sub M} (k, t) is self-similar in time and well modeled by a broken power law with subinertial and inertial range indices very close to 7/2 and –2, respectively. The magnetic coherence scale is found to grow in time as t {sup 2/5}, much too slow to account for optical polarization of gamma-ray burst afterglow emission if magnetic energy is to be supplied only at microphysical length scales. No bursty or explosive energy loss is observed in relativistic MHD turbulence having modest magnetization, which constrains magnetic reconnection models for rapid time variability of GRB prompt emission, blazars, and the Crab nebula.

• OSTI ID: 22364562
• Journal Information: Astrophysical Journal Letters, Vol. 794, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
AFTERGLOW
COSMIC GAMMA BURSTS
CRAB NEBULA
ENERGY LOSSES
ENERGY SPECTRA
MAGNETIC FIELDS
MAGNETIC RECONNECTION
MAGNETIZATION
MAGNETOHYDRODYNAMICS
NEUTRON STARS
POLARIZATION
RELATIVISTIC RANGE
TURBULENCE