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Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Astrophysics and Astronomy

2004

Magnetic fields

Articles 1 - 2 of 2

Full-Text Articles in Physical Sciences and Mathematics

Self‐Consistent Diffusive Lifetimes Of Weibel Magnetic Fields In Gamma‐Ray Bursts, C. H. Jaroschek, H. Lesch, R. A. Treumann Dec 2004

Self‐Consistent Diffusive Lifetimes Of Weibel Magnetic Fields In Gamma‐Ray Bursts, C. H. Jaroschek, H. Lesch, R. A. Treumann

Dartmouth Scholarship

Weibel filamentation in relativistic plasma shell collisions has been demonstrated as an efficient and fast mechanism for the generation of near-equipartition magnetic fields in self-consistent particle-in-cell (PIC) simulations. In generic γ-ray burst (GRB) models with kinetically dominated plasma outflow, sufficient strength and lifetime of magnetic fields are essential to validate synchrotron emission as the source of radiative outbursts. In this article we report on self-consistent PIC simulations of pair-plasma shell collisions in the highly relativistic regime with particle ensembles up to 5 × 108. Energy dependence of magnetic field generation in the Weibel process is discussed, and for …


New Nonthermal Filaments At The Galactic Center: Are They Tracing A Globally Ordered Magnetic Field?, Ted La Rosa, Michael E. Nord, Joseph W. Lazlo, Namir E. Kassim May 2004

New Nonthermal Filaments At The Galactic Center: Are They Tracing A Globally Ordered Magnetic Field?, Ted La Rosa, Michael E. Nord, Joseph W. Lazlo, Namir E. Kassim

Faculty and Research Publications

New high-resolution, wide-field 90 cm VLA observations of the Galactic center (GC) region by Nord and coworkers have revealed 20 nonthermal filament (NTF) candidates. We report 6 cm polarization observations of six of these. All of the candidates have the expected NTF morphology, and two show extended polarization, confirming their identification as NTFs. One of the new NTFs appears to be part of a system of NTFs located in the Sgr B region, 64 pc in projection north of Sgr A. These filaments cross the Galactic plane with an orientation similar to the filaments in the Galactic center radio arc. …