London – Scientists at the Australian National University (ANU) have discovered that Andromeda, the closest galaxy to the Milky Way, has destroyed several smaller galaxies in the last billion years, a study published Wednesday in the journal Nature revealed .
The experts, led by Dougal Mackey of the ANU and Geraint Lewis of the University of Sydney, identified, in large streams of stars, the remains of these ancient galaxies, which were smaller than Andromeda and that were swallowed up to 10,000 million years ago , when it was still forming.
Dougal Mackey highlighted the importance of the finding by pointing out forecasts that the Milky Way will collide with Andromeda in about 4,000 million years, hence it is useful to "know what kind of monster our galaxy faces to discover the final destination of the Milky Way. "RELATED
"Andromeda has a stellar halo much larger and more complex than the Milky Way, indicating that it has cannibalized many more galaxies, possibly larger than this," said Mackey.
In 2018, another study by an international team revealed that Andromeda ended two million years ago with a massive galaxy, sister of the Milky Way.
Mackey explained that by tracking down the remains of these smaller galaxies with embedded star clusters, scientists were able to analyze the way Andromeda attracted and swallowed them.
This study has shed light on how the Milky Way has grown and evolved over billions of years, a goal that experts were pursuing, according to Mackey, "to understand how these systems were formed and evolved."
"We are cosmic archaeologists who, instead of in human history, dig in the fossils of dead galaxies a long time ago," said Professor Geraint Lewis.