There is increasing evidence that galaxies have grown by merging with other galaxies. Telescopes like Hubble have detected dozens of interacting galaxies, including famous galaxies like Arp 248. The Andromeda galaxy is the closest major galaxy to the Milky Way, and a new study shows our neighbor swallowed other galaxies in two different epochs.

“A few years ago, we discovered that on the far outskirts of Andromeda, in objects in its orbit, that the galaxy was not grazing, it ate in large quantities in two different epochs,” said Jerent Lewis of the University of Sydney. .

Lewis is lead author of a new paper entitled “Chemodynamic infrastructure in M31’s inner globular cluster halo: further evidence for recent accumulation.” Monthly Notices of the Royal Astronomical Society will publish the article and is currently in preparation for publication on arxiv.org.

“This new result offers a clearer picture of how our local universe came together – telling us that at least one of the larger galaxies is occasionally fed by smaller galaxies,” Lewis said in a press release.

Globular clusters are the focus of this study. These are older associations of lower metallic stars. There are at least 150 in the Milky Way, possibly more. They play a role in galactic evolution, but this role is not fully understood. Globular clusters as they are known are more common in halo galaxies, while their corresponding diffuse clusters are found in galactic disks.

The researchers behind this study identified a population of spheres with the same metallicity in Andromeda’s inner halo. Metallicity belongs to the basic composition of stars, while elements heavier than hydrogen and helium are called metals in astronomy. Globular stars have a lower metallicity than most stars in the same region, meaning they came from the other side rather than Andromeda itself. This also means that they are older because there were fewer heavy elements in the early universe than there is now.

Lewis named the collection the spherical structure Dulai Structure, which means black flow in Welsh. The Duhlet structure is probably a group of 10 to 20 sphericals displaced by the rotation of Andromeda. But this isn’t the only global group of animals to be misplaced. The Duhle structure is evidence that Andromeda has been feeding on a group of global animals for the last 5 billion years. Another group is a subpopulation of globes that suggested a second feeding 8 to 10 billion years ago. According to Lewis and his co-authors, globular clusters have lower metallicity and are also kinematically different from other clusters in the same region. As the Andromeda Galaxy spins in one direction, the Dyulet structure spins in the other. Source