Why the discovery of hot gas between galaxies is exciting Canadian researchers

A team of international researchers led by an astrophysicist from the University of British Columbia has discovered a young galaxy cluster that was producing hot gas at a rate five times greater than theoretically possible.

The discovery is exciting astrophysicists, who say it could change the way scientists think about the early evolution of the universe after the Big Bang.

Published in Nature magazine More than two dozen researchers from around the world participated in the study Monday. They studied a galaxy cluster called SPT2349-56, located about 12 billion light years away.

Researchers led by UBC PhD candidate Dazhi Zhou have discovered that significant amounts of hot gas are being produced in the space between galaxies.

Zhou said it was the first detection of such hot gas so early in the universe, given that the galaxy cluster in question is considered “young” in cosmic terms, forming just 1.4 billion years after the Big Bang.

“This is kind of a big leap in our understanding of how the universe works,” he told CBC News.

James Di Francesco, director of the Dominion Astrophysical Observatory, north of Victoria, says previous theoretical ideas were that galaxy clusters don't get that hot that quickly.

Di Francesco said the gas between galaxies is generally expected to get hotter over time as the galaxies orbit and inject energy into the gas around them.

“However, something caused this gas in this very young cluster to heat up sharply at a very early age,” said the astrophysicist, who was not involved in the study.

“And so this is revolutionary to the extent that it opens a new window in understanding how these clusters develop and [it's] goes against our expectations.”

Early History of the Universe

Zhou said the amount of hot gas the researchers detected only existed billions of years after the galaxy cluster SPT2349-56 formed.

Researchers made the discovery using a series of telescopes in Chile, allowing them to peer into dark clouds, delve deeper into star formation and explore the earliest times of our Universe.

Zhou said the telescopes observe at short wavelengths called submillimeter and millimeter wavelengths—colloquially known as radio telescopes.

The scientist said they allowed researchers to estimate how hot the gas was despite being so far from Earth.

“When you use a radio telescope to look at the sky, we can see a tiny shadow, and when there is enough hot gas, that signal is quite independent. [of] distance,” he said.

WATCH | Various telescopes provide ultra-high resolution images of the Universe:

Telescope images provide first Ultra HD images of the Universe

The Vera C. Rubin Observatory in Chile has released the first images of the universe taken by the world's largest digital camera inside a massive telescope. Scientists say ultra-high-definition images will enable revolutionary space exploration.

A galaxy cluster refers to a collection of galaxies with clusters and superclusters of galaxies that may contain hundreds to thousands of these galaxies.

Our Milky Way belongs to the Virgo Supercluster, potentially home to more than 2,000 galaxies.

Zhou says the new research will have important implications for understanding modern massive galaxy clusters and how they form.