The interaction of a magnetohydrodynamical shock with a filament
| Autor: | Julian M. Pittard, K. J. A. Goldsmith |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
Physics
Shock wave Field (physics) Condensed matter physics FOS: Physical sciences Astronomy and Astrophysics Astrophysics 01 natural sciences Astrophysics - Astrophysics of Galaxies Shock (mechanics) Magnetic field Protein filament Quantitative Biology::Subcellular Processes symbols.namesake Mach number Space and Planetary Science Beta (plasma physics) Astrophysics of Galaxies (astro-ph.GA) 0103 physical sciences symbols Magnetohydrodynamics 010306 general physics 010303 astronomy & astrophysics |
| Popis: | We present 3D magnetohydrodynamic numerical simulations of the adiabatic interaction of a shock with a dense, filamentary cloud. We investigate the effects of various filament lengths and orientations on the interaction using different orientations of the magnetic field, and vary the Mach number of the shock, the density contrast of the filament, and the plasma beta, in order to determine their effect on the evolution and lifetime of the filament. We find that in a parallel magnetic field filaments have longer lifetimes if they are orientated more 'broadside' to the shock front, and that an increase in the density contrast hastens the destruction of the cloud, in terms of the modified cloud-crushing time-scale, tcs. The combination of a mild shock and a perpendicular or oblique field provides the best condition for extending the life of the filament, with some filaments able to survive almost indefinitely since they are cocooned by the magnetic field. A high value for the density contrast does not initiate large turbulent instabilities in either the perpendicular or oblique field cases but rather draws the filament out into long tendrils which may eventually fragment. In addition, flux ropes are only formed in parallel magnetic fields. The length of the filament is, however, not as important for the evolution and destruction of a filament. 30 pages, 42 figures, accepted by MNRAS |
| Databáze: | OpenAIRE |
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