English: This composite image shows the central region of the spiral galaxy NGC 4151. In the center, X-rays (blue) from the Chandra X-ray Observatory are combined with optical data (yellow) showing positively charged hydrogen from observations with the 1-meter Jacobus Kapteyn Telescope on La Palma in the Canary Islands. The red around the center shows neutral hydrogen detected by radio observations with the National Science Foundation's Very Large Array in New Mexico. 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 toward the center of the galaxy. The yellow blobs around the red ellipse are regions where star formation has recently occurred. Credit: X-rays, NASA/CXC/CfA/J.Wang et al.; optical, Isaac Newton Group of Telescopes, La Palma/Jacobus Kapteyn Telescope; radio, NSF/NRAO/VLA