After gathering data from NASA’s Chandra X-Ray Observatory, with the help of radio observations and computer simulations, an international team of scientists has discovered a vast wave of hot gas in the proximity of Perseus galaxy cluster. The wave was found be of 200,000 light years-old, about twice the size of our own Milky Way Galaxy.

According to the findings of the researchers, the wave formed billions of years ago, after a small galaxy cluster grazed Perseus, causing its vast supply of gas to slosh around an enormous volume of space.

Galaxy clusters are the largest structured bound by gravity in the Universe today. About 11 million light-years across, and located about 240 million light-years away, the Perseus galaxy cluster is named for its host constellation. Most of its observable matter takes the form of a pervasive gas, averaging tens of millions of degrees, being so hot, that it only glows in X-rays.

After a series of simulations, the formation of the bay was explained. The researchers found that gas, which is located in a large cluster, similar to Perseus, has settled into two components, a “cold” central region with temperatures around 54 million degrees Fahrenheit, and a surrounding zone here the gas is three times hotter. Moreover, a small galaxy cluster containing about a thousand times the mass of the Milky Way skirts the larger cluster, missing its center by around 650,000 light-years.

The flyby creates a gravitational disturbance that churns the gas like cream stirred into coffee, eventually creating and expanding the spiral of cold gas. About after 2.5 billion years, when the gas has risen nearly 500,000 light years from the center, vast waves form and roll at its periphery for hundreds of millions of years before dissipating.

It was found that the size of the waves correspond to the strength of the cluster’s magnetic field. In the case where it is too weak, the waves will reach much larger sizes compared to those observed. If the waves are too strong, the clusters will not form at all. The study eventually allowed astronomers to probe the magnetic field throughout the entire volume of the clusters, being a measurement that is impossible to make by any other means.