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Title: SCALING LAW OF RELATIVISTIC SWEET-PARKER-TYPE MAGNETIC RECONNECTION

Abstract

Relativistic Sweet-Parker-type magnetic reconnection is investigated by relativistic resistive magnetohydrodynamic (RRMHD) simulations. As an initial setting, we assume anti-parallel magnetic fields and a spatially uniform resistivity. A perturbation imposed on the magnetic fields triggers magnetic reconnection around a current sheet, and the plasma inflows into the reconnection region. The inflows are then heated due to ohmic dissipation in the diffusion region and finally become relativistically hot outflows. The outflows are not accelerated to ultrarelativistic speeds (i.e., Lorentz factor {approx_equal} 1), even when the magnetic energy dominates the thermal and rest mass energies in the inflow region. Most of the magnetic energy in the inflow region is converted into the thermal energy of the outflow during the reconnection process. The energy conversion from magnetic to thermal energy in the diffusion region results in an increase in the plasma inertia. This prevents the outflows from being accelerated to ultrarelativistic speeds. We find that the reconnection rate R obeys the scaling relation R{approx_equal}S{sup -0.5}, where S is the Lundquist number. This feature is the same as that of non-relativistic reconnection. Our results are consistent with the theoretical predictions of Lyubarsky for Sweet-Parker-type magnetic reconnection.

Authors:
 [1];  [2];  [3];  [4]
  1. Center for Computational Astrophysics, National Astronomical Observatory of Japan, 2-21-1, Osawa, Mitaka, Tokyo 181-8588 (Japan)
  2. Division of Theoretical Astronomy, National Astronomical Observatory of Japan, 2-21-1, Osawa, Mitaka, Tokyo 181-8588 (Japan)
  3. Department of Computational Science, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501 (Japan)
  4. Kwasan and Hida Observatories, Graduate School of Science, Kyoto University, Kyoto 607-8471 (Japan)
Publication Date:
OSTI Identifier:
21565429
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal Letters
Additional Journal Information:
Journal Volume: 739; Journal Issue: 2; Other Information: DOI: 10.1088/2041-8205/739/2/L53; Journal ID: ISSN 2041-8205
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; DISTURBANCES; ENERGY CONVERSION; MAGNETIC FIELDS; MAGNETIC RECONNECTION; MAGNETOHYDRODYNAMICS; SCALING LAWS; SIMULATION; CONVERSION; FLUID MECHANICS; HYDRODYNAMICS; MECHANICS

Citation Formats

Takahashi, Hiroyuki R., Kudoh, Takahiro, Masada, Youhei, and Matsumoto, Jin, E-mail: takahashi@cfca.jp. SCALING LAW OF RELATIVISTIC SWEET-PARKER-TYPE MAGNETIC RECONNECTION. United States: N. p., 2011. Web. doi:10.1088/2041-8205/739/2/L53.
Takahashi, Hiroyuki R., Kudoh, Takahiro, Masada, Youhei, & Matsumoto, Jin, E-mail: takahashi@cfca.jp. SCALING LAW OF RELATIVISTIC SWEET-PARKER-TYPE MAGNETIC RECONNECTION. United States. doi:10.1088/2041-8205/739/2/L53.
Takahashi, Hiroyuki R., Kudoh, Takahiro, Masada, Youhei, and Matsumoto, Jin, E-mail: takahashi@cfca.jp. Sat . "SCALING LAW OF RELATIVISTIC SWEET-PARKER-TYPE MAGNETIC RECONNECTION". United States. doi:10.1088/2041-8205/739/2/L53.
@article{osti_21565429,
title = {SCALING LAW OF RELATIVISTIC SWEET-PARKER-TYPE MAGNETIC RECONNECTION},
author = {Takahashi, Hiroyuki R. and Kudoh, Takahiro and Masada, Youhei and Matsumoto, Jin, E-mail: takahashi@cfca.jp},
abstractNote = {Relativistic Sweet-Parker-type magnetic reconnection is investigated by relativistic resistive magnetohydrodynamic (RRMHD) simulations. As an initial setting, we assume anti-parallel magnetic fields and a spatially uniform resistivity. A perturbation imposed on the magnetic fields triggers magnetic reconnection around a current sheet, and the plasma inflows into the reconnection region. The inflows are then heated due to ohmic dissipation in the diffusion region and finally become relativistically hot outflows. The outflows are not accelerated to ultrarelativistic speeds (i.e., Lorentz factor {approx_equal} 1), even when the magnetic energy dominates the thermal and rest mass energies in the inflow region. Most of the magnetic energy in the inflow region is converted into the thermal energy of the outflow during the reconnection process. The energy conversion from magnetic to thermal energy in the diffusion region results in an increase in the plasma inertia. This prevents the outflows from being accelerated to ultrarelativistic speeds. We find that the reconnection rate R obeys the scaling relation R{approx_equal}S{sup -0.5}, where S is the Lundquist number. This feature is the same as that of non-relativistic reconnection. Our results are consistent with the theoretical predictions of Lyubarsky for Sweet-Parker-type magnetic reconnection.},
doi = {10.1088/2041-8205/739/2/L53},
journal = {Astrophysical Journal Letters},
issn = {2041-8205},
number = 2,
volume = 739,
place = {United States},
year = {2011},
month = {10}
}