Their light is breaking up the molecu-lar hydrogen and heating up the gas in the cloud. When the gas gets hotter, it starts moving faster and eventually escapes from the nebula. The less dense parts of the nebula are evap-orated by the stars' radiation first, leaving behind these columns. In this image, again, the colours of the gas indicate which atoms are emitting light in that area. This time red is sulphur, green is hydrogen and blue is oxygen.
Lets look again.
The upper edge of the cloud has a somewhat ragged shape. This is not due to the sun rays pushing the rest of the cloud down, it is because the cloud is mushrooming inside a massive atmosphere which inhibits its growth. The shape of the Eagle Nebula is formed by gases and dust which are mushrooming and growing inside the massive space-time fluid. Therefore, it looks exactly like a cloud. The light at the crest of the galactic clouds comes from stars behind the clouds, hence the observed brilliant diffraction.