1999/04/03 by S. N. Shore, Steven N. Shore, T. N. LaRosa +1 · 5 citations
Physics and Astronomy · #Astro and Planetary Science #Astrophysics and Star Formation Studies #Solar and Space Plasma Dynamics #astro-ph
paper · pdf · doi:10.1086/307601
Uses AAS aasms4.sty macros. ApJ (in press, vol. 521, 20 Aug)
arxiv created 1999/04/03 · openalex publication_date 1999/08/20 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
We propose a model for the origin of the isolated nonthermal filaments observed at the Galactic center based on an analogy to cometary plasma tails. We invoke the interaction between a large-scale magnetized galactic wind and embedded molecular clouds. As the advected wind magnetic field encounters a dense molecular cloud, it is impeded and drapes around the cloud, ultimately forming a current sheet in the wake. This draped field is further stretched by the wind flow into a long, thin filament the aspect ratio of which is determined by the balance between the dynamical wind and amplified magnetic field pressures. The key feature of this cometary model is that the filaments are dynamic configurations, and not static structures. As such, they are local amplifications of an otherwise weak field and not directly connected to any static global field. The derived field strengths for the wind and wake are consistent with observational estimates. Finally, the observed synchrotron emission is naturally explained by the acceleration of electrons to high energy by plasma and MHD turbulence generated in the cloud wake.