Astronomy and Astrophysics – Astrophysics – High Energy Astrophysical Phenomena
Scientific paper
2012-02-11
New Journal of Physics, 14, 023007, 2012
Astronomy and Astrophysics
Astrophysics
High Energy Astrophysical Phenomena
Scientific paper
10.1088/1367-2630/14/2/023007
The expansion of an initially unmagnetized planar rarefaction wave has recently been shown to trigger a thermal anisotropy-driven Weibel instability (TAWI), which can generate magnetic fields from noise levels. It is examined here if the TAWI can also grow in a curved rarefaction wave. The expansion of an initially unmagnetized circular plasma cloud, which consists of protons and hot electrons, into a vacuum is modelled for this purpose with a two-dimensional particle-in-cell (PIC) simulation. It is shown that the momentum transfer from the electrons to the radially accelerating protons can indeed trigger a TAWI. Radial current channels form and the aperiodic growth of a magnetowave is observed, which has a magnetic field that is oriented orthogonal to the simulation plane. The induced electric field implies that the electron density gradient is no longer parallel to the electric field. Evidence is presented here for that this electric field modification triggers a second magnetic instability, which results in a rotational low-frequency magnetowave. The relevance of the TAWI is discussed for the growth of small-scale magnetic fields in astrophysical environments, which are needed to explain the electromagnetic emissions by astrophysical jets. It is outlined how this instability could be examined experimentally.
Borghesi Marco
Bret Antoine
Dieckmann Mark Eric
Drury Luke O'C.
Kourakis Ioannis
No associations
LandOfFree
PIC simulation of a thermal anisotropy-driven Weibel instability in a circular rarefaction wave 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 PIC simulation of a thermal anisotropy-driven Weibel instability in a circular rarefaction wave, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and PIC simulation of a thermal anisotropy-driven Weibel instability in a circular rarefaction wave will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-238114