A team of astronomers from the Netherlands Institute for Space Research (SRON) used the Chandra X-ray Space Telescope to observe the galaxy cluster ZwCl 2341 + 0000 for 55 hours. They first saw one of the stages of a collision of galaxies, which resembles a sharp cone in shape.

Collisions of galaxy clusters go through different stages. Astronomers have models of this process at different stages. At the first stage, the colliding galaxies look like a blur, then they take the shape of a cone and at the end they become like a tongue. So far, astronomers have not observed the cone-shaped transitional period of the collision.

“The cone stage is very fleeting, so we are glad we managed to catch it,” said study co-author Aurora Simonescu.

Most galaxies are found in hundreds and thousands of clusters. There is a lot of space between them, filled with hot gas, which is called the intra-cluster medium. It is very hot, hundreds of millions of degrees Celsius. Galaxies drift past each other unharmed while clusters collide with each other.

Scientists have previously performed X-ray observations of the massive galaxy cluster ClG-J104803.7 + 313843 using data from ESA’s XMM-Newton spacecraft. The results of the observational campaign, published on the arXiv.org website, gave scientists more data on the properties of this cluster.