Three-dimensional numerical study of converging flux events.
Abstract
The first self-consistent three-dimensional magnetohydrodynamical simulations of converging magnetic flux events associated with the formation of coronal X-ray bright points are presented. The initial magnetic field results from two magnetic dipoles located below the photosphere at positions {vec}(r)_1_ and {vec}(r)_2_, respectively, and an additional horizontal magnetic field parallel to the line <{vec}(r)_1vec(r)_2_>. Both dipole moments are vertical and have equal magnitude but opposite orientation. During the dynamical evolution, a prescribed photospheric convection pattern causes the magnetic dipole-like structures to approach one another. In the early phase of the evolution a current sheet forms in the central region above the polarity inversion line. When the current density exceeds a critical value, anomalous resistivity due to microturbulence is assumed to break the ideal Ohm's law. As a consequence, magnetic reconnection sets in and results in a jet-like plasma flow. The localized plasma heating associated with the reconnection process might account for the flaring of tiny filaments within bright point structures.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- July 1997
- Bibcode:
- 1997A&A...323..593D
- Keywords:
-
- SOLAR CORONA;
- X-RAY BRIGHT POINTS;
- SOLAR MAGNETIC FIELDS;
- MHD SIMULATIONS;
- PLASMAS