An artist's concept of what two merging supermassive black holes might look like. Each one is surrounded by an accretion disk of hot gas and material streaming away via jets. CourtesyNASA, ESA, Joseph Olmsted
View of Milkdromeda from Earth “shortly” after the galactic merger of the Milky Way and Andromeda, around 3.85-3.9 billion years from now. Credit: NASA, ESA, Z. Levay and R. van der Marel , T. Hallas, and A. Mellinger HST’s image of the galaxy MCG-03-34-064 in visible light. Two of the three bright spots at the core are active galactic nuclei sources of light and X-ray emissions. They indicate two supermassive black holes about 300 light-years apart and growing closer. Image credit: NASA, ESA, Anna Trindade Falcão
This illustration shows the merger of two supermassive black holes and the gravitational waves that ripple outward as the black holes spiral toward each other. Credit: LIGO/T. Pyle