Evolution of magnetic fields in supernova remnants

Abstract

Supernova remnants (SNR) are now widely believed to be a source of cosmic rays (CRs) up to an energy of 1015 eV. Electrons (and possibly protons) are accelerated at the forward shock through diffusive shock acceleration. The magnetic fields required to accelerate CRs to sufficiently high energies need to be much higher than can result from compression of the circumstellar medium (CSM) by a factor 4, as is the case in strong shocks. Non-thermal synchrotron maps of these regions indicate that indeed the magnetic field is much stronger. How these magnetic fields get enhanced is not yet fully understood. We use an adaptive mesh refinement MHD code, AMRVAC, to simulate the evolution of supernova remnants and their magnetic fields. For now, we evaluate the ideal MHD equations to follow the evolution of the SNR with different configurations of the initial magnetic field and CSM. We have also started to incorporate test particles in order to track cosmic ray acceleration in the remnant.