Decoding Galactic History: How the Milky Way’s Disk Thickness Tells the Tale of Cosmic Collisions

The study reveals the Milky Way’s merger history through its disk thickness, using stellar age data and simulations. Key events include the Gaia-Sausage-Enceladus merger 11 billion years ago and interactions with the Sagittarius dwarf galaxy. Simulations confirm these patterns, showing a transition from a thick to thin disk over billions of years. Despite uncertainties, the findings provide a robust method to trace galactic evolution.