Our neighbouring galaxy is ready to eat us

  • Dougal Mackey, ANU
Date:10 October 2019 Author: Leila Stein Tags:,

The Andromeda galaxy has been swallowing smaller surrounding galaxies for aeons. Now, in a recently published study, scientists have been looking into it’s cannibalistic past to determine how well the Milky Way will fare against it’s ravenous neighbour.

There’s no need to worry, however, as the expected collision between the two galaxies is only expected to happen in about four billion years. In the meantime, researchers are studying Andromeda to find out more about how this massive galaxy came to be.

Scientists analysed Andromeda’s bigger stellar halo and were able to see groups of stars that are part of several smaller galaxies, which were devoured over the last few billion years.

“By tracing the faint remains of these smaller galaxies with embedded star clusters, we’ve been able to recreate the way Andromeda drew them in and ultimately enveloped them at the different times,” said Dr Mackey said from the ANU Research School of Astronomy and Astrophysics in a statement.

“Andromeda has a much bigger and more complex stellar halo than the Milky Way, which indicates that it has cannibalised many more galaxies, possibly larger ones.”

The study, published in Nature, analysed data from the Pan-Andromeda Archaeological Survey, known as PAndAS operated by the Canada–France–Hawaii Telescope on the summit of Mauna Kea, Hawai’i.

According to Vice, PAndAS  focuses on reconstructing the origins, evolution, and current structure of Andromeda, making it part of a special astronomical subfield called “galactic archeology.”

“Knowing what kind of a monster our galaxy is up against is useful in finding out the Milky Way’s ultimate fate,” said Mackey.

Image:Wikicommons and Dougal Mackey, ANU.

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