The Galactic Center Isolated Nonthermal Filaments as Analogs of Cometary Plasma Tails

We propose a model for the origin of the isolated nonthermal filamentsobserved at the Galactic center based on an analogy to cometary plasma tails.We invoke the interaction between a large scale magnetized galactic wind andembedded molecular clouds. As the advected wind magnetic field encounters adense molecular cloud, it is impeded and drapes around the cloud, ultimatelyforming a current sheet in the wake. This draped field is further stretched bythe wind flow into a long, thin filament whose aspect ratio is determined bythe balance between the dynamical wind and amplified magnetic field pressures.The key feature of this cometary model is that the filaments are dynamicconfigurations, and not static structures. As such, they are localamplifications of an otherwise weak field and not directly connected to anystatic global field. The derived field strengths for the wind and wake areconsistent with observational estimates. Finally, the observed synchrotronemission is naturally explained by the acceleration of electrons to high energyby plasma and MHD turbulence generated in the cloud wake.Comment: Uses AAS aasms4.sty macros. ApJ (in press, vol. 521, 20 Aug