A team of astronomers using the Hubble Space Telescope found an unambiguous link between the presence of supermassive black holes that power high-speed, radio-signal-emitting jets and the merger history of their host galaxies. Almost all galaxies with the jets were found to be merging with another galaxy, or to have done so recently
A NASA/ESA Hubble Space Telescope (HST) view of the magnificent spiral galaxy NGC 4603, the most distant galaxy in which a special class of pulsating stars called Cepheid variables have been found. It is associated with the Centaurus cluster, one of the most massive assemblages of galaxies in the nearby universe.
Located approximately 300 million light-years away in the constellation of Volans, AM 0644-741 is one of the most spectacular ‘Ring Galaxies’ we currently know. - Image Credit: NASA, ESA, and The Hubble Heritage Team (AURA/STScI)