Researchers discovered an unknown fusion between the Milky Way galaxy and the Kraken galaxy 11 billion years ago.
The Milky Way contains more than 100 billion stars. At least dozens of times over the past 12 billion years, the Milky Way has collided with neighboring galaxies and merged, “devouring” neighboring stars and mixing them together in star nurseries. After each merger, the shape, size and movement of the Milky Way changed forever, becoming the characteristic spiral shape it is today.
In research published in the Monthly Notices of the Royal Astronomical Society, scientists are studying the cause of this spiral. Using artificial intelligence (AI) to join clusters by age, motion, and chemical makeup, the team found evidence of five large-scale galaxy mergers (each comprising 100 million). star), dating back more than 10 billion years, includes an ancient collision never described before.
The recently discovered collision with the Kraken galaxy not only helped fill in the mysterious family tree of the Milky Way galaxy, but also helped astronomers sequence our galactic forms in the early days. According to lead researcher Diederik Kruijssen, an astronomer at the University of Heidelberg in Germany, the Kraken collision event is the most significant merger the Milky Way has ever seen. The merger took place 11 billion years ago, when the Milky Way was four times smaller than it is today.
In the new study, Kruijssen and his colleagues used computer simulations to analyze all globular clusters, long-standing solid spheres containing up to 1 million stars that form at the same time in the Milky Way. Our galaxy includes at least 150 of these clusters. Astronomers claim that these are “fossils” of ancient galaxies “swallowed up” by the Milky Way in history.
The team developed an AI algorithm to identify the spherical cluster based on the star’s common characteristics. First, they ran the algorithm on thousands of simulated galaxies. Once the algorithm can accurately predict the formation, evolution and destruction of globular clusters in the simulated galaxies, they use it for the Milky Way.
Using data from the Gaia space probe, an algorithm that analyzes the age, movement and chemical makeup of known globular clusters to reconstruct the fusions that brought them there. The team’s analysis accurately predicts four past mergers of the Milky Way, including the Gaia merger that helped add billions of stars to our galaxy 9 billion years ago with the Fusion by Kraken.
According to the researchers’ results, Kraken is the oldest and most important galactic collision in the history of the Milky Way. This fusion occurred when the Milky Way was only a fraction of its current size, resulting in 13 globular clusters still identifiable today. The team suspects at least 15 other mergers in the past, each with at least 10 million stars.