page.section.full_url = {{ page.section.full_url or home }}

Millions AND billions!

This enormous galaxy cluster, seen by our Hubble Space Telescope (@NASAHubble), contains the mass of a staggering three million billion suns! Nicknamed “El Gordo” (“the Fat One” in Spanish), it is the largest, hottest and brightest X-ray galaxy ever discovered in the distant Universe. Galaxy clusters are the largest objects in the Universe that are bound together by gravity. They form over billions of years as smaller groups of galaxies slowly come together. In 2012, observations showed that El Gordo is actually composed of two galaxy clusters colliding at millions of kilometers per hour. The formation of galaxy clusters depends heavily on dark matter and dark energy; studying such clusters can therefore help shed light on these elusive phenomena. In 2014, Hubble found that most of El Gordo’s mass is concealed in the form of dark matter. Evidence suggests that El Gordo’s “normal” matter — largely composed of hot gas that is bright in the X-ray wavelength domain — is being torn from the dark matter in the collision. The hot gas is slowing down, while the dark matter is not. Credit: ESA/Hubble & NASA, RELICS
The Conversation
Don’t miss a thing
What matters in tech, in your inbox daily
Follow us on
Link in bio. 👀
Link in profile.