4 galaxy clusters collide 3 billion light-years from Earth

4 clusters of galaxies, each hundreds of trillion times the mass of the Sun, will gradually merge into a giant structure.

Astronomers use data from the Chandra X-ray Observatory and a number of other telescopes to synthesize a detailed picture of the collision, Phys reported on October 25. The galaxy cluster is the largest structure in the universe linked by gravity. Each cluster contains hundreds, even thousands of galaxies, surrounded by hot gas, and contains large amounts of invisible dark matter. Collisions of two galactic clusters will sometimes occur. Collisions with more galaxy clusters are also rare.

Two pairs of galaxies 3 billion light years from Earth prepare to collide and merge.(Photo: NASA).

In the new image, two pairs of galaxies are on their way to colliding and form a building block called Abell 1758 . Each pair of two galaxy clusters is in the process of merging. Scientists first discovered Abell 1758 in 2004 using data from Chandra and the European Space Agency's XMM-Newton satellite (ESA).

With the pair above, the central part of each cluster once passed each other, about 300 to 400 million years ago. In the future, they will turn around. The lower pair consists of two clusters approaching for the first time.

The blue and white areas indicate the amount of hot or weak radiant heat. This is also the first time Chandra has captured the shock wave image in the hot air in the upper pair. From this shockwave, the team estimates, two clusters of galaxies are traveling at a relative speed of 3-5 million km / h.

The new image also shows how elements heavier than helium in clusters of galaxies are mixed and redistributed. This process depends on the process of collision and merger. Abell 1758 is an ideal case to study because the upper and lower pairs are at different stages.

With the pair below, the heaviest elements are concentrated at the center of the two galaxies, which means their initial positions haven't changed much. With the pair above, the collision and merger have progressed further, the position of the heavy elements is greatly affected. The places they are most concentrated are located between the two centers of galaxy clusters and to the left.

Collisions between galaxies affect the inner galaxy as well as the hot air surrounding them. According to data from the MMT Observatory in Arizona, some galaxies are moving much faster than the rest of the clusters, possibly influenced by the gravitational force of the collision.

1. Two galaxy clusters contain hundreds of billions of stars about to collide
2. The two galaxies collide 424 million light-years from Earth