Explanation

There is very weak 10 micro Gauss magnetic field in the interstellar medium. Let's simulate the expansion of the supernova remnant when such magnetic field exists.

	[Initial Condition] We assume isotropic interstellar gas with constant density and constant magnetic field (which has inclination angle 60 degree to the vertical direction of the screen) with 0.5 plasma beta. Perturbation is given as 10% pressure increase at the origin and followed its evolution. In the figure, color shows density, arrows show velocity, and lines show magnetic field lines.
	[Propagation Stage] Central high temperature and high pressure gas sweeps surrounding gas and expands in the shell form. But its propagation toward vertical direction of the magnetic field is prevented by magnetic tension. Density is decreasing from Red, to Orange, Olive, Green, Aqua, Blue, Perple, and Black.