About 2.8 billion light years from the Earth, two galaxy clusters are engaged in a cosmic discomfort. These huge structures last hit a billion years ago, but now it seems that they will return to the second round.
Galaxy clusters involved in this Scuffle are part of a larger system – a “combined” cluster of galaxies – called PSZ2 G181. In a study published in The Astrophysical Journal In April, researchers analyzed new PSZ2 G181 observations that suggest that their constituent clusters are ready to break each other for the second time.
The main collisions between galaxy clusters are generally considered rare, according to the European Space Agency (ESA), but repeated collisions are decidedly more unusual. In addition, the total mass of PSZ2 G181 is low characteristic compared to other combined galaxy clusters that have resulted in collisions, adding another layer of peculiarity to the findings.
Astronomers know the individual galaxy clusters that form PSZ2 G181, crashed with each other once before thanks to previous radio observations, according to a NASA statement.
This work revealed regions in the form of fuzzy radio emission parentheses on the outskirts of the system. These structures were probably formed as a result of the initial collision a billion years ago.
This new study, directed by Andra Stroe, a postdoctoral colleague of the Harvard & Smithsonian Center for Astrophysics, further validates the idea that a previous collision occurred. The researchers analyzed new PSZ2 G181 observations of two X-ray observatories: NASA Chandra and XMM-NEWton from the European Space Agency. His study identified a cold gas bridge that connected the two clusters, which probably resulted in gas spending during the first collision, according to his report.
Over the last billion years, the two clusters have separated and now sit at about 11 million light years from each other. This is the largest separation between this type of structure that astronomers have ever seen, according to the NASA statement.
But Stroe and his colleagues found evidence that suggest that these galaxy clusters are now back in a collision course. The team discovered three more fronts aligned with the previous collision axis: a potential sign of a second, approaching.
The discovery of this rare event provides a new view of the dynamics of galaxy clusters, especially those that involve low mass systems, which are not explored. As researchers point out, finding low -dough -clusted radio emissions such as PSZ2 G181 is difficult, but “with the arrival of new generation x -rays and surveys, we may discover the” tip of the iceberg “, they say in its report.
