NASA reveals 'megatsunami' of hot gas twice the size of the Milky Way rolling through the Perseus galaxy cluster

Galaxy is 11 million light-years across and located 240 million light-years away

Wave formed billions of years ago, after a small galaxy cluster grazed Perseus and caused its vast supply of gas to slosh around an enormous volume of space

Flyby creates  disturbance that churns up the gas like cream stirred into coffee

This animation dissolves between two different views of hot gas in the Perseus galaxy cluster. The first is Chandra's best view of hot gas in the central region of the Perseus cluster, where red, green and blue indicate lower-energy to higher-energy X-rays, respectively. The larger image incorporates additional data over a wider field of view. It has been specially processed to enhance the contrast of edges, revealing subtle structures in the gas. The wave is marked by the upward-arcing curve near the bottom, centered at about 7 o'clock.

GALAXY CLUSTERS 

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

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HOW THEY SOLVED THE MYSTERY

To solve the mystery, Walker and his colleagues turned to existing Chandra observations of the Perseus cluster to further investigate the bay. 

They combined a total of 10.4 days of high-resolution data with 5.8 days of wide-field observations at energies between 700 and 7,000 electron volts. 

For comparison, visible light has energies between about two and three electron volts. 

The researchers say the wave formed billions of years ago, after a small galaxy cluster grazed Perseus and caused its vast supply of gas to slosh around an enormous volume of space. This X-ray image of the hot gas in the Perseus galaxy cluster was made from 16 days of Chandra observations. Researchers then filtered the data in a way that brightened the contrast of edges in order to make subtle details more obvious. An oval highlights the location of an enormous wave found to be rolling through the gas.