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 modeling.gcfilaments.latex  ApJ in press 2002
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astro-ph/0112378

\documentclass[12pt,preprint]{aastex}
\begin{document} 

\title{Modeling the Galactic Center Nonthermal
Filaments as Magnetized Wakes} \author{Russell~B.  Dahlburg}

\affil{Laboratory for Computational Physics \& Fluid Dynamics, Naval
Research Laboratory, Washington, DC 20375-5344}

\email{rdahlbur@lcp.nrl.navy.mil} 

\author{Giorgio Einaudi}

\affil{Dipartimento di Fisica e Istituto Nazionale Fisica Materia,
Sez.  A, Universit\`a di Pisa, 56100, Pisa, ITALIA}

\email{einaudi@df.unipi.it} 

\author{T.~N.  LaRosa} 

\affil{Department
of Biological and Physical Sciences, Kennesaw State University, 1000
Chastain Rd., Kennesaw, GA 30144} 

\email{ted@avatar.kennesaw.edu}

\author{Steven~N.  Shore} 

\affil{Department of Physics \& Astronomy,
Indiana University South Bend, 1700 Mishawaka Avenue, South Bend, IN
46634-7111} 

\email{sshore@paladin.iusb.edu} 
%\bigskip

\begin{abstract} 
We simulate the Galactic Center nonthermal filaments as magnetized
wakes formed dynamically from amplification of a weak (tens of $\mu$G)
global magnetic field through the interaction of molecular clouds with
a Galactic Center wind.  One of the key issues in this {\it cometary
model} is the stability of the filament against dynamical disruption.
Here we show 2-dimensional MHD simulations for interstellar conditions
that are appropriate for the Galactic Center. The structures
eventually disrupt through a shear driven nonlinear instability but
maintain coherence for lengths up to 100 times their width as
observed. The final instability, which destroys the filament through
shredding and plasmoid formation, grows quickly in space (and time)
and leads to an abrupt end to the structure, in accord with
observations.  As a by-product, the simulation shows that emission
should peak well downstream from the cloud-wind interaction site. 
\end{abstract}