The recently discovered victim of the Milky Way galaxy has been named Pontus, estimated to have been consumed about 8-10 billion years ago.
The Milky Way galaxy, which contains Earth, has been shown in numerous studies to be a “monster” that has swallowed at least 16 other galaxies to achieve its massive size today. Utilizing data from the European Space Agency’s Gaia spacecraft, which maps galaxies, a team of scientists from the Max Planck Institute for Astronomy (Germany) has discovered traces of Pontus.
The Milky Way and its satellite galaxies, stellar streams, where the purple squares indicate the clusters of objects incorporated into the Milky Way by Pontus – (Image: Gaia/ESA)
All that remains are the “cosmic fossils” drifting in the halo of the Milky Way, which is the extended region outside the main disk of the galaxy.
According to Sci-News, Dr. Khyati Malhan, the lead author of the study, explains that when a foreign galaxy falls into the Milky Way, a strong gravitational force tears it into a vast stellar stream that extends all the way to the halo.
The research team examined a total of 170 globular clusters, 41 stellar streams, and 46 satellites of the Milky Way and found that 25% of these objects belong to six distinct groups, representing six merger events, with the “monster” Milky Way acting as the “predator.”
Among these, the sixth merger is a previously unidentified event. This is Pontus, which was consumed about 8-10 billion years ago and has not yet been completely crushed by the Milky Way. Therefore, instead of stars being scattered everywhere, there are still quite large remnants clustered in certain areas of the galaxy’s halo.
The most recent identified galaxy swallowing event was the Sagittarius galaxy, which is known to have fallen into the Milky Way about 5-6 billion years ago.
The study was recently published in the Astrophysical Journal.
