SCALING LAW OF RELATIVISTIC SWEET-PARKER-TYPE MAGNETIC RECONNECTION

Journal Article · Sat Oct 01 04:00:00 EDT 2011 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/739/2/L53· OSTI ID:21565429

Takahashi, Hiroyuki R ^[1]; Kudoh, Takahiro ^[2]; Masada, Youhei ^[3]; Matsumoto, Jin ^[4]

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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)

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.

• OSTI ID: 21565429
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 2 Vol. 739; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
CONVERSION
DISTURBANCES
ENERGY CONVERSION
FLUID MECHANICS
HYDRODYNAMICS
MAGNETIC FIELDS
MAGNETIC RECONNECTION
MAGNETOHYDRODYNAMICS
MECHANICS
SCALING LAWS
SIMULATION