ESO Very Large Telescope Captures Spectacular Cosmic Crash

ESO's Very Large Telescope (VLT) has given scientists their best ever look at a spectacular cosmic collision. Researchers now have a view of the motion of gas being ripped out of a galaxy as it smashes into a vast galaxy cluster at high speed.

In this case, the researchers used the Multi Unit Spectroscopic Explorer instrument on the VLT to watch ESO 137-001, a spiral galaxy located about 200 million light-years away in the southern constellation of The Southern Triangle. This allowed the scientists to get the best view yet of what exactly is happening to the galaxy as it hurtles toward the Norma Cluster.

It turns out that the galaxy is being robbed of its raw materials by a process called ram-pressure stripping, which occurs when an object moves at high speed through a liquid or gas. This is similar to how air blows a dog's hair back when it sticks its head out of the window of a moving car. As it falls at several million kilometers per hour toward the galaxy cluster, the galaxy is being stripped of most of its gas, the fuel needed to make the next generation of young stars. In fact, it's likely that the galaxy will turn into a gas-poor red galaxy.

"It is one of the major tasks of modern astronomy to find out how and why galaxies in clusters evolve from blue to red over a very short period of time," said Michele Fumagalli, one of the researchers, in a news release. "Catching a galaxy right when it switches from one to the other allows us to investigate how this happens."

The findings reveal a bit more about the evolution of galaxies. Scientists estimate that eventually, all of the galactic gas will be swept away into bright streaks behind the galaxy, forming magnificent tails.

The findings are published in the journal Monthly Notices of the Royal Astronomical Society.