  The youngest Galactic supernova remnant G1.9+0.3 shows a discrete feature
between its radio and X-ray morphologies. The observed radio morphology
features a single maximum in the north, while the X-ray observation shows two
opposite 'ears' on the east and west sides. Using 3D magneto hydrodynamical
simulations, we investigate the formation of the discrete feature of the
remnant. We have tested different parameters for better simulation and
reproduced similar discrete features under an environment with density gradient
and an environment with clump, which provides a possible explanation of the
observation.
