1. A new time-dependent finite-difference method for relativistic shock acceleration.
- Author
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Delaney, S., Dempsey, P., Duffy, P., and Downes, T. P.
- Subjects
- *
FINITE differences , *SYNCHROTRONS , *PARALLEL algorithms , *GALAXY clusters , *PLASMA gases , *MOMENTUM distributions - Abstract
ABSTRACT We present a new approach to calculate the particle distribution function about relativistic shocks including synchrotron losses using the method of lines with an explicit finite-difference scheme. A steady, continuous, one-dimensional plasma flow is considered to model thick (modified) shocks, leading to a calculation in three dimensions plus time, the former three being momentum, pitch angle and position. The method accurately reproduces the expected power-law behaviour in momentum at the shock for upstream flow speeds ranging from 0.1 c to 0.995 c (Γ∈ (1, 10]). It also reproduces approximate analytical results for the synchrotron cutoff shape for a non-relativistic shock, demonstrating that the loss process is accurately represented. The algorithm has been implemented as a hybrid OpenMP-MPI parallel algorithm to make efficient use of SMP cluster architectures and scales well up to many hundreds of CPUs. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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