Color composite of a galaxy with radio jets
This is a composite color image showing radio emission in blue, visible light in green, and infrared light (3.6 microns) in red. The galaxy in middle is a radio source. An "engine" in the middle generates radio emission locally and also expels jets of relativistic particles. They generate radio emission of their own, creating the blue "lobes" above and below the galaxy. The field, which is about 1/15 the size of the full Moon, shows many other galaxies, most fainter than the radio galaxy. Relatively nearby galaxies show up as yellow or green because they are bright in visible light. More distant galaxies tend to be redder and are often only visible in the infrared. The green stripe is an image flaw created because the star in the upper left was too bright for the camera.