Hubble Space Telescope Views “El Gordo”
In 2014, astronomers using the NASA/ESA Hubble Space Telescope found that this enormous galaxy cluster contains the mass of a staggering three million billion Suns — so it’s little wonder that it has earned the nickname of “El Gordo” (“the Fat One” in Spanish)! Known officially as ACT-CLJ0102-4915, it is the largest, hottest, and X-ray brightest galaxy cluster 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 from ESO’s Very Large Telescope, NASA’s Chandra X-ray Observatory and the Atacama Cosmology Telescope showed that El Gordo is actually composed of two galaxy clusters colliding at millions of kilometres 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.
This image was taken by Hubble’s Advanced Camera for Surveys and Wide-Field Camera 3 as part of an observing programme called RELICS (Reionization Lensing Cluster Survey). RELICS imaged 41 massive galaxy clusters with the aim of finding the brightest distant galaxies for the forthcoming NASA/ESA/CSA James Webb Space Telescope (JWST) to study.
Credit: ESA/Hubble & NASA, RELICS
- Asteroid 2012 TC4 Will Safely Pass By Earth, Just Above Communications Satellites
- Astronomers View Near-Earth Asteroid 2014 HQ124 as it Passes Earth
- Hubble Space Telescope Views Dwarf Galaxy NGC 178
- Scientists Find Evidence of ‘Orphan’ Gamma-Ray Bursts
- Discovery Provides Clues to How Galaxies and Black Holes Develop Together
- Investigating the Mysterious Pops of Light Spotted by NASA Satellite
- New Cassini Image of Saturn’s Moons Janus and Mimas
- Cassini Spacecraft’s Final View of Saturn’s Moon Pandora
- Cassini Spacecraft Made Its Final Close Approach to Saturn’s Moon Mimas
- Cassini Views “The Great Eye” of Saturn’s Moon Mimas
- Three Times the Fun: New Cassini Image of Tethys, Enceladus and Mimas
- Astronomers Model the Effects of Water Loss on Exoplanets
- NASA’s Solar Dynamics Observatory Spots a Lunar Transit
- 2014 – The Highest Global Mean Sea Surface Temperatures Ever Recorded