Dalhousie prof helps find galaxy cluster with hot gas 1.4 billion years after Big Bang

These colourful display of lights against the night sky was captured by cameraman Tom Stefanac on April 22, 2017.

More than a billion years ago, a galaxy cluster burned with an intensity that far exceeds the predictions of current models, according to a study co-authored by a Dalhousie University professor.

The study, led by Canadian researchers and an international team of astronomers, focused on a “baby” galaxy cluster called SPT2349-56 from roughly 12 billion years ago, according to a news release from Dalhousie. They used a series of radio telescopes built by the National Research Council of Canada.

The cluster was found 1.4 billion years after the Big Bang. It blazed with gas that was five times hotter than predicted in current models.

“This tells us that something in the early universe, likely three recently discovered supermassive black holes in the cluster, were already pumping huge amounts of energy into the surroundings and shaping the young cluster, much earlier and more strongly than we thought,” said co-author Dr. Scott Chapman, a professor at Dalhousie University, in the release.

According to the release, the infant cluster measures roughly 500,000 light years across, which is comparable to the size of the halo surrounding the Milky Way. It contained more than 30 active galaxies and forms stars more than 5,000 times faster than our own galaxy.

“Understanding galaxy clusters is the key to understanding the biggest galaxies in the universe,” said Chapman. “These massive galaxies mostly reside in clusters and their evolution is heavily shaped by the very strong environment of the clusters as they form, including the intracluster medium.”

The release says current models suggest massive reservoirs of gas form the intracluster medium, and are then collected and heated by gravitational interactions as an unstable galaxy cluster matures.

The new findings suggest that this birth is more explosive and could require scientists to rethink the speed of galaxy cluster evolution.

“We want to figure out how the intense star formation, the active black holes and this overheated atmosphere interact, and what it tells us about how present galaxy clusters were built,” said lead author Dazhi Zhou. ”How can all of this be happening at once in such a young, compact system?”