Katsuaki Higashimori, Masahiro Hoshino
We perform a two-dimensional simulation by using an electromagnetic hybrid
code to study the formation of slow-mode shocks in collisionless magnetic
reconnection in low beta plasmas, and we focus on the relation between the
formation of slow shocks and the ion temperature anisotropy enhanced at the
shock downstream region. It is known that as magnetic reconnection develops,
the parallel temperature along the magnetic field becomes large in association
with the anisotropic PSBL (plasma sheet boundary layer) ion beams, and this
temperature anisotropy has a tendency to suppress the formation of slow shocks.
Based on our simulation result, we found that the slow shock formation is
suppressed due to the large temperature anisotropy near the X-type region, but
the ion temperature anisotropy relaxes with increasing the distance from the
magnetic neutral point. As a result, two pairs of current structures, which are
the strong evidence of dissipation of magnetic field in slow shocks, are formed
at the distance x > 115 ion inertial lengths from the neutral point.
View original:
http://arxiv.org/abs/1201.4213
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