Open AccessNon‐linear amplification of a magnetic field driven by cosmic ray streaming
Author(s) -
Lucek S. G.,
Bell A. R.
Publication year - 2000
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2000.03363.x
Subject(s) - physics , cosmic ray , magnetic field , astrophysics , ultra high energy cosmic ray , acceleration , supernova , shock wave , amplitude , field (mathematics) , cosmic cancer database , computational physics , astronomy , classical mechanics , optics , mechanics , mathematics , quantum mechanics , pure mathematics
One‐, two‐ and three‐dimensional numerical results of the non‐linear interaction between cosmic rays and a magnetic field are presented. These show that cosmic ray streaming drives large‐amplitude Alfvénic waves. The cosmic ray streaming energy is very efficiently transferred to the perturbed magnetic field of the Alfvén waves, and the non‐linear time‐scale of the growth of the waves is found to be very rapid, of the order of the gyro‐period of the cosmic ray. Thus, a magnetic field of interstellar values, assumed in models of supernova remnant blast wave acceleration, would not be appropriate in the region of the shock. The increased magnetic field reduces the cosmic ray acceleration time and so increases the maximum cosmic ray energy, which may provide a simple and elegant resolution to the highest energy Galactic cosmic ray problem, where the cosmic rays themselves provide the fields necessary for their acceleration.