Astronomy and Astrophysics – Astrophysics
Scientific paper
Mar 2009
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009rema.book.....g&link_type=abstract
Relativistic Magnetohydrodynamics, by K. N. Gourgouliatos.
Astronomy and Astrophysics
Astrophysics
Scientific paper
Many, yet unresolved, questions in astrophysics are associated to the presence of electromagnetic fields. These include problems of solar magnetohydrodynamics, where a significant amount of observational data is available but also relativistic systems involving the launch of jets from γ-ray bursts. Motivated by these phenomena, we study a series of problems of magnetohydrodynamics. Our task is to study systems where analytical solutions are possible so that we obtain an understanding of their physical behaviour. For this purpose, we study separable solution of force-free magnetic fields and we then apply them in systems of arcade topology. This problem is motivated by the arcade structures observed on the surface of the Sun before coronal mass ejections. We assume a magnetic arcade, emerging from the surface of a spherical conductor where the magnetic field is radially self-similar. Then, because of differential rotation on the surface of the conductor the field lines are twisted and energy is injected in the system. Assuming force-free magnetic fields the system reacts in two ways, a toroidal component is introduced and the poloidal flux expands. No matter how slow the rate of differential rotation is, the predicted expansion velocity becomes very rapid at late stages. This is the limitation of the non-relativistic magnetohydrodynamics approximation. The rest of this thesis is about problems of relativistic magnetohydrodynamics. We present the analogue of force-free magnetic fields for systems of spherical geometry, first derived by Prendergast (2005) and we expand it to systems of cylindrical geometry. We derive analytical and semi-analytical solutions of electromagnetic fields emerging from a central explosion in vacuum and in the presence of a co-expanding fluid. The mathematical description of this problem leads to a set of non-linear partial differential equations. As it is impossible to find general solutions for this set of equations, we assume self-similar solutions. We discuss applications of these explosions to γ-ray bursts.
No associations
LandOfFree
Relativistic Magnetohydrodynamics does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Relativistic Magnetohydrodynamics, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Relativistic Magnetohydrodynamics will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1731986