The image you see below shows Chandra's first picture, the SNR of Cassiopea A. Now move your cursor to the image. Now you can see the same nebula-picture shot by a German X-ray telescope almost a decade ago.
Explanation:
The X ray was allegedly emitted by high temperature due to the collision of the SNR with the interstellar matter. But, already the ROSAT-picture was not consistent with this collision-model because ROSAT clearly showed that the emission of edges of the SNR is less intensive than those of the inner regions (white). Chandra also confirms this inconsistency. But now, Chandra´s fine filaments totally exclude a collision ! These filaments on the edge are similar to the antennas of a beetle which fly free in the air. These fine floating filaments are not pressed to the body of the SNR by any hindrance. The whole body of this SNR consists of about 190 filaments (I predicted 100 see table 1), they would clearly show a hindrance if any existed. (Also the spot-penumbra or the corona contains 100-200 filaments. Why ? I do not know.)
Important note: The two images are both over 40 KB, so it might take some time until this swapimage gets loaded!