Filament Cooling and Condensation in a Sheared Magnetic Field

  1. C. T. Russell,
  2. E. R. Priest and
  3. L. C. Lee
  1. Gerard Van Hoven

Published Online: 21 MAR 2013

DOI: 10.1029/GM058p0315

Physics of Magnetic Flux Ropes

Physics of Magnetic Flux Ropes

How to Cite

Van Hoven, G. (1990) Filament Cooling and Condensation in a Sheared Magnetic Field, in Physics of Magnetic Flux Ropes (eds C. T. Russell, E. R. Priest and L. C. Lee), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM058p0315

Author Information

  1. Department of Physics, University of California, Irvine, California 92717

Publication History

  1. Published Online: 21 MAR 2013
  2. Published Print: 1 JAN 1990

ISBN Information

Print ISBN: 9780875900261

Online ISBN: 9781118663868

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Keywords:

  • Solar photosphere;
  • Magnetic flux;
  • Astrophysics

Summary

Thermal instability driven by optically thin radiation in the corona is believed to initiate the formation of solar filaments [Parker, 1953]. The fact that filaments are observed generally to separate regions of opposite, line-of-sight, magnetic polarity in the differentially rotating photosphere suggests that filament formation requires the presence of a highly sheared magnetic field. In this paper we discuss the coupled energetics and dynamics of the most important condensation modes, those due to perpendicular thermal conduction at short wavelengths. We describe their linear structure in the sheared field and their growth rates. We have also performed two-dimensional, nonlinear, magnetohydrodynamic simulations of the evolution of these modes in a force-free field. To clarify the essential physics of the nonlinear behavior, we have traced the evolution of generic perturbations possessing broad spatial profiles. The simulations achieve the fine thermal structures, minimum temperatures and maximum densities characteristic of observed solar filaments.