The merging of quasiperpendicular collisionless shocks
- Astronomy Program, Department of Physics and Astronomy, University of Maryland, College Park, MD (USA)
The overtaking of one collisionless shock by another is studied by means of hybrid numerical simulations. The two shocks merge into a stronger shock and trailing nonshock discontinuities. The strong shock continues to propagate in the same direction as the two weaker shocks. The merging is shown to occur by a self-consistent process involving the interaction of ions reflected at the overtaking shock with the plasma upstream of the leading shock. The characteristic time scale for the merging is typically {Omega}{sup {minus}1}{sub {ital i}}, where {Omega}{sub {ital i}} is the ion gyrofrequency. For exactly perpendicular shocks, the trailing discontinuity is a tangential discontinuity. It has a width of 2--3 ion Larmor radii. For oblique shocks, a contact discontinuity is present in the downstream plasma state. These results are of relevance to shock interactions in the very distant solar wind as well as in other energetic astrophysical situations such as solar flares.
- OSTI ID:
- 6149875
- Journal Information:
- Physics of Fluids B; (USA), Vol. 2:10; ISSN 0899-8221
- Country of Publication:
- United States
- Language:
- English
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