What happens when galaxy clusters collide?
You get phenomena like the Bullet cluster. Read on to find out what it tells us in our understanding of the universe
The Bullet cluster is currently the best evidence we have to support the theory of dark matter
This concentrated region of galaxies found in the Carina constellation is commonly known as the Bullet cluster and it’s one of the hottest galactic collisions found in space.
It’s made up of two clusters, the smaller of which passed through the other 150 million years ago, creating a shock wave as gas that was heated to 70 million degrees Celsius (158 million degrees Fahrenheit) passed through even hotter 100-million-degree-Celsius gas (212 million Fahrenheit) at a speed of 9.66 million kilometres an hour (six million miles an hour). The result was an incredible output of energy equivalent to ten quasars.
This composite image shows visible light recorded by the Hubble and Magellan telescopes, plus X-ray emissions (pink) recorded by the Chandra telescope. Dark matter was indirectly observed by the gravitational lensing of objects in the background.
Image Credit: NASA