Scientists from the University of Colorado Boulder have developed a technique that can help astronomers find thousands of merging galaxies.

A team of scientists developed a computer program that scans the night sky and looks for signs of galactic mergers. This includes the resulting shape of the merging galaxies and how the stars inside are moving.

They will present their findings at the 233rd Meeting of the American Astronomical Society in Seattle, Washington.

The Hunt For Galaxy Mergers

Galaxy mergers — when two or more galaxies collide — takes place over billions of years. Although, sometimes, they produce bursts of light, finding galactic mergers is not easy. For some, the signs are not always obvious. 

"People have been looking at pictures of galaxies and saying, 'that's a merger" or 'that's not a merger,'" explained Rebecca Nevin, a graduate student who worked on the project. "But people are also really bad at doing that, and they miss a lot of galaxies."

However, until now, no technique can determine whether a galaxy is merging or not. 

To address this issue, Nevin and her team created computer simulations that mimic all the possible ways that two or more galaxies might merge. They then used these simulations to train a computer program to look at observations and recognize the telltale signs of merging galaxies.

To test, the scientists fed the computer programs real-life images of merging galaxies from the Sloan Digital Sky Survey (SDSS) that created the most detailed three-dimensional map of the night sky.

The computer program was able to accurately identify merging galaxies 80 percent of the time.

The team said they will continue to improve the program. They are already working on incorporating measurements in which stars within two merging galaxies move.

The Evolution Of Galaxies

"These simulated galaxy mergers allow us to follow billions of years of evolution directly, whereas observations of real galaxies are limited to single moments in time," added Laura Blecha, an assistant professor at the University of Florida who was also involved in the project.

The scientists hope that the computer program can aid astronomers to figure out how often these galactic mergers occur and how it will shape the future of the universe.

The study is now available via the pre-print archive

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