This false color image, taken by the Einstein Observatory, shows Puppis A in x-ray wavelengths. It looks very different from the visible photograph, largely because x-ray emission comes from hot gas while optical light is from ΓÇ£shockedΓÇ¥ gas. As the supernovaΓÇÖs shock front expands, it heats the interstellar material it encounters. It also acts as a kind of plow, pushing material before it and leaving behind only some large clumps and extremely hot, diffuse gas. The denser material at the edges, which can cool more easily, emits only lower energy optical photons.
This image shows the standard asymmetric shape of many supernova remnants. The amorphism occurs because the shape of the supernova remnant is