2002/06/22 by F. Thomsen, Frederik Birkebæk Thomsen, Åke Nordlund +3
Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics (astro-ph) #Astrophysics and Star Formation Studies #FOS: Physical sciences #Gamma-ray bursts and supernovae #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0206394
14 pages, 9 figures, submitted to Astronomy and Astrophysics
arxiv created 2002/06/22 · openalex publication_date 2002/06/22 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We have performed 3-D numerical magnetohydrodynamic (MHD) jet experiments to study the instabilities associated with strongly toroidal magnetic fields and determine if such magnetic configurations in jets are as unstable as similar situations are found to be in the laboratory and in analytical estimates. A perfectly conducting Keplerian disc with fixed density, rotational velocity and pressure is used as a lower boundary for the jet. The energy equation is solved, with the inclusion of self-consistently computed heating by viscous and magnetic dissipation. The resulting jets evolve into time-dependent, non-axisymmetric configurations, but we find only minor disruption of the jets by for example the kink instability. We find that magnetic dissipation may have profound effects on the jet flow as: 1) it turns on in highly wound up magnetic field regions and helps to prevent critical kink situations; 2) it influences jet dynamics by re-organizing the magnetic field structure and increasing thermal pressure in the jet; and 3) it influences mass loading by increasing temperature and pressure at the base of the jet.