An international group of astronomers, using multiple telescopes, was recently able to collect an impressive view of the Ring of Fire at the core of the spiral galaxy NGC 4151. The formation looks mesmerizing, and represents one of the clearest views of this region ever collected. This is obviously a composite image, where each color represents a distinct set of wavelengths. The component added by the NASA Chandra X-ray Observatory is shown in blue, whereas the 1-meter Jacobus Kapteyn Telescope at the La Palma Observatory shows visible light data in yellow. The red ring shows neutral hydrogen detected by radio observations with the NSF’s Very Large Array. This neutral hydrogen is part of a structure near the center of NGC 4151 that has been distorted by gravitational interactions with the rest of the galaxy, and includes material falling towards the center of the galaxy.
The yellow blobs around the red ellipse are regions where star formation has recently occurred. A recent study shows the X-ray emission probably was caused by an outburst powered by the supermassive black hole located in the white region in the center of the galaxy. Evidence for this idea comes from the elongation of the X-rays running from the top left to the bottom right and details of the X-ray spectrum. There are also signs of interactions between a central source and the surrounding gas, particularly the yellow arc of H II emission located above and to the left of the black hole. NGC 4151 is located about 43 million light years away from the Earth and is one of the nearest galaxies that contains an actively growing black hole.