Three-dimensional numerical investigations of the morphology of type Ia   SNRs
  We explore the morphology of Type Ia supernova remnants (SNRs) using three-dimensional hydrodynamics modeling and an exponential density profile. Our model distinguishes ejecta from the interstellar medium (ISM), and tracks the ionization age of shocked ejecta, both of which allow for additional analysis of the simulated remnants. We also include the adiabatic index as a free parameter, which affects the compressibility of the fluid and emulates the efficiency of cosmic ray acceleration by shock fronts. In addition to generating 3-D images of the simulations, we compute line-of-sight projections through the remnants for comparison against observations of Tycho's SNR and SN 1006. We find that several features observed in these two remnants, such as the separation between the fluid discontinuities and the presence of ejecta knots ahead of the forward shock, can be generated by smooth ejecta without any initial clumpiness. Our results are consistent with SN 1006 being dynamically younger than Tycho's SNR, and more efficiently accelerating cosmic rays at its forward shock. We conclude that clumpiness is not a necessary condition to reproduce many observed features of Type Ia supernova remnants, particularly the radial profiles and the fleecy emission from ejecta at the central region of both remnants. 
D. C. Warren, J. M. Blondin
astro-ph.GA