Internal Structure of a CME: Theory and Observation*

Jonathan Krall

Abstract

A recent program of direct comparison of model CME results and CME observations [1,2,3] has produced a coherent view of the 3D geometry and the dynamics of a specific class of CME's, which we refer to as ``flux-rope CME's.'' We now extend this effort to provide a consistent view of the internal structure of flux-rope CME's. This view is based on a magnetic flux-rope model of CME's, on synthetic coronagraphs of these model CME's, and on the direct comparison of model results with observations from numerous sources, chiefly the LASCO and MK3 coronagraphs and the Extreme-ultraviolet Imaging Telescope (EIT).  We find that the parts of the flux rope which have field lines that are connected to the solar surface (toroidal field lines) tend to have a lower density than the remainder of the flux rope. This low-density region corresponds to the current-channel in the center of the flux rope, outside of which the field lines are entirely poloidal.

[1] Chen et al., ApJ Lett., 490, L191, 1997.

[2] Chen et al., to appear in ApJ, 1999.

[3] Krall et al., submitted to ApJ, 1999.

*Work supported by ONR.

     Authors: J. Krall, J. Chen, R.T. Duffin, R.A. Howard, B.J. Thompson

  Organization: NRL
     Telephone: (202) 404 7719
           Fax: (202) 767 0631
        e-mail: krall@ppdu.nrl.navy.mil
       Address: Plasma Physics Division, Code 6794
   Naval Research Lab.
   Washington, DC, 20375-5346