This image shows the x-ray emis- sion from a huge halo of very hot gas surrounding M87. Although it is easy to see here, the halo is faint in visible light. The bright center indicates that x-ray emission is most intense near the galaxyΓÇÖs core. So much energy emanating from so small a source near the galactic center would seem to confirm the existence of a supermassive black hole.
By outlining the gas surrounding the galaxy, x-ray images such as this demonstrate the gravitational attraction of invisible mass and thereby help to reveal the presence of unseen material, known as dark matter. Dark matter is the principle component of M87ΓÇöand possibly of the entire universe.
