If you think our Milky Way galaxy is big for those 100,000 light-years that it measures from one edge to the opposite, you should think about a galaxy cluster more often. That’s the place where hundreds of galaxies ‘meet’.
Therefore, it’s absolutely normal to ask yourself what’s it like inside a massive galaxy cluster. Astronomers had been wondering the same thing. According to Space.com, they had been using almost 200 lasers to replicate the extreme heat that can be found in galaxy clusters.
More info is needed about the conditions inside galaxy clusters
It wasn’t expected that in the area inside galaxy clusters, hydrogen gas could create temperatures that are at the same level as the ones from the Sun’s center. Scientists want to understand how such horrible conditions persist, which is why they’re investigating using a very energetic laser facility known as the National Ignition Facility, from Lawrence Livermore National Laboratory in California. The same conditions are recreated in a very small environment that would easily fit in a bottle.
The University of Chicago explained in an issued statement quoted by Space.com:
The scientists focused 196 lasers onto a single tiny target, creating a white-hot plasma with intense magnetic fields that exists for a few billionths of a second,
This was long enough for them to determine that instead of a uniform temperature, there were hot and cold spots in the plasma. This dovetails with one of the theories that has been proposed for how heat is trapped inside galaxy clusters.
The galaxies existing in galaxy clusters are held together due to mutual gravitational attraction. A typical galaxy cluster stretches across 30 million light-years. This means 300 times larger than the diameter of our own Milky Way galaxy. A galaxy cluster can even contain thousands of galaxies.