New study finds link between cosmic collisions and solar wind

A new study, led by Helen Russell of the University of Nottingham in the United Kingdom, has found a connection between some of the most energetic events in the Universe and much weaker ones powered by the Sun.

Using NASA's flagship Chandra X-ray observatory, the researchers observed Abell 2146, a pair of colliding galaxy clusters located about 2.8 billion light-years from Earth, for a total of about 23 days.

Galaxy clusters, one of the largest structures in the cosmos, contain hundreds of galaxies and huge amounts of hot gas and dark matter. When they collide, they release enormous amounts of energy unlike anything witnessed since the big bang, as is the case of Abell 2146.

In this composite image of Abell 2146, Chandra X-ray data (purple) shows hot gas, and Subaru Telescope optical data shows galaxies (red and white). The hot gas in the former is pushing out a shock wave, about 1.6 million light-years long, as it collides with the hot gas in the other cluster. A second shock wave of similar size is seen behind the collision.

The two shock fronts in Abell 2146 are among the brightest and clearest shock fronts known among galaxy clusters. Shock waves like those generated by a supersonic jet are collisional shocks, involving direct collisions between particles. In Earth's atmosphere near sea level, gas particles typically travel only about 4 millionths of an inch before colliding with another particle, NASA said in a statement.

On the contrary, in galaxy clusters and solar wind, direct collisions between particles occur too rarely to produce shock waves because the gas is so diffuse, with incredibly low density.

The researchers studied the gas temperature behind the shock waves in the two colliding galaxy clusters and showed that electrons have been mainly heated by compression of gas by the shock, an effect like that seen in the solar wind.

What do colliding galaxy clusters and the solar wind have in common?Both include shock waves generated by charged particles and magnetic fields.Scientists used NASA's @chandraxray observatory to see how the cosmic collisions are like the solar wind.https://t.co/xSrYKuUfo3 pic.twitter.com/u7xZhUOW6u

— NASA Sun & Space (@NASASun) June 7, 2022