Evolution of Magnetic Fields and Cosmic Ray Acceleration in Supernova Remnants - Astrophysics > Astrophysics of GalaxiesReportar como inadecuado




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Abstract: Observations show that the magnetic field in young supernova remnants SNRsis significantly stronger than can be expected from the compression of thecircumstellar medium CSM by a factor of four expected for strong blast waves.Additionally, the polarization is mainly radial, which is also contrary toexpectation from compression of the CSM magnetic field. Cosmic rays CRs mayhelp to explain these two observed features. They can increase the compressionratio to factors well over those of regular strong shocks by adding arelativistic plasma component to the pressure, and by draining the shock ofenergy when CRs escape from the region. The higher compression ratio will alsoallow for the contact discontinuity, which is subject to the Rayleigh-TaylorR-T instability, to reach much further out to the forward shock. This couldcreate a preferred radial polarization of the magnetic field. With an adaptivemesh refinement MHD code AMRVAC, we simulate the evolution of SNRs with threedifferent configurations of the initial CSM magnetic field, and look at twodifferent equations of state in order to look at the possible influence of a CRplasma component. The spectrum of CRs can be simulated using test particles, ofwhich we also show some preliminary results that agree well with availableanalytical solutions.



Autor: K.M. Schure, J. Vink, A. Achterberg, R. Keppens

Fuente: https://arxiv.org/







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