Modeling the Galactic Center Nonthermal Filaments as Magnetized Wakes

Russell B. Dahlburg (1), Giorgio Einaudi (2), T. N. LaRosa (3), Steven N. Shore (4)


(1) Laboratory for Computational Physics & Fluid Dynamics, Naval Research Laboratory, Washington, DC 20375-5344
(2) Dipartimento di Fisica e Istituto Nazionale Fisica Materia, Sez. A, Università di Pisa, 56100, Pisa, ITALIA
(3) Department of Biological and Physical Sciences, Kennesaw State University, 1000 Chastain Rd., Kennesaw, GA 30144
(4) Department of Physics & Astronomy, Indiana University South Bend, 1700 Mishawaka Avenue, South Bend, IN 46634-7111

Paper: ApJ in press 2002

EPrint Server: astro-ph/0112378


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 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.


Preprints available from the authors at ted@avatar.kennesaw.edu , or the raw TeX (no figures) if you click here.

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