Simulation of the growth of the 3D RayleighTaylor instability in supernova remnants using an expanding reference frame
Abstract
Context. The RayleighTaylor instabilities that are generated by the deceleration of a supernova remnant during the ejectadominated phase are known to produce fingerlike structures in the matter distribution that modify the geometry of the remnant. The morphology of supernova remnants is also expected to be modified when efficient particle acceleration occurs at their shocks.
Aims: The impact of the RayleighTaylor instabilities from the ejectadominated to the SedovTaylor phase is investigated over one octant of the supernova remnant. We also study the effect of efficient particle acceleration at the forward shock on the growth of the RayleighTaylor instabilities.
Methods: We modified the Adaptive Mesh Refinement code RAMSES to study with hydrodynamic numerical simulations the evolution of supernova remnants in the framework of an expanding reference frame. The adiabatic index of a relativistic gas between the forward shock and the contact discontinuity mimics the presence of accelerated particles.
Results: The great advantage of the supercomoving coordinate system adopted here is that it minimizes numerical diffusion at the contact discontinuity, since it is stationary with respect to the grid. We propose an accurate expression for the growth of the RayleighTaylor structures that smoothly connects the early growth to the asymptotic selfsimilar behaviour.
Conclusions: The development of the RayleighTaylor structures is affected, although not drastically, if the blast wave is dominated by cosmic rays. The amount of ejecta that reaches the shocked interstellar medium is smaller in this case. If acceleration were to occur at both shocks, the extent of the RayleighTaylor structures would be similar but the reverse shock would be strongly perturbed.
 Publication:

Astronomy and Astrophysics
 Pub Date:
 June 2010
 DOI:
 10.1051/00046361/200912692
 arXiv:
 arXiv:1002.5048
 Bibcode:
 2010A&A...515A.104F
 Keywords:

 ISM: supernova remnants;
 acceleration of particles;
 hydrodynamics;
 Astrophysics  High Energy Astrophysical Phenomena
 EPrint:
 15 pages, 12 figures, accepted for publication in Astronomy and Astrophysics with minor editorial changes. Version with full resolution images can be found at http://www.lpl.arizona.edu/~ffrasche/~12692.pdf